Let's not distort the functional term of "user friendly". In the business world, "user friendly" refers to increasing sales by giving customers what they want and what will make them comfortable when they shop. In brick and mortar, it means stores hours that target the widest possible market, primary market targeted in-store music, wide aisles, appealing product display, easy to read signage, clearly marked prices, popular products located in main aisles and plenty of eager staff to answer product questions.
We must use the words "shop" and "customer" when thinking of user-friendliness for websites, because the entire purpose of Adsense ads is to get an advertiser's potential "customer" to find their site where they will then "shop", or at least come to browse, later arriving and shopping. If your site is for little Mensa members, who come to read every single word on the page and THEN view your ads, you are one of a small percentage of webmasters, with a very unique visitor base. People in general do not read an entire article and will never see that ad block beneath it.
If it's not about the money, instead being about the visitor, then pull the ads. People who don't want to shop are annoyed by ads, so get rid of them. If the purpose of the site is to make money, than you do what you must to ensure you make the most amount of money and still be able to sleep at night. Nobody goes into business with the idea that they want to make only a buck a day. If you only want an ad below the article, down at the bottom of your page, you are greatly misinformed about the behavior of those who arrive to read.
You assume, wrongly so, that everyone who comes to your site comes with the intent of reading the ENTIRE article. That is why your ad is at the bottom of the article. In the narrow thinking scheme of things, you would be right. However, if you really are a 'writer', then you know that the first paragraph or two of your article is actually a summary of the points you are going to make in the article. Subsequent paragraphs describe those points, with the final paragraph giving a conclusional wrap-up. While that final paragraph may mean a difference between an A grade and B grade on a term paper, it doesn't mean squat on an 'informational' page. The only way that last paragraph is useful, is where the link to the next page is located there. For a one-page article, is pretty useless.
A person of average intelligent will get all the information they need in the first couple, well-written paragraphs, then is ready to leave your page (unless it is a forum page). They will NEVER see that ad block at the bottom of the article.
Not everybody wants to know step by step how the bridge was built. Some just want to know where the bridge was built, the cost of the bridge, what color it was, what year it was built, how many died building the bridge, who the primary engineer was OR any other single facts related to the bridge. They are not going to read the entire article, because, because, because.... you will not tell them ANY of those facts in the last paragraph, unless you are really BAD writer. These facts are sprinkled throughout the article.
Let me give a specific example of this. You rank #1 for "longest bridge". When I search for some facts I know to get a refined search for what I don't know, I search for, "longest bridge built in 1941". You pop up and I click through to your site, because what I want to know is where that bridge is located. I don't care about any other facts. So, as soon as you tell me in your article, where that bridge is built, I am done reading. I now know where it is located. To this point, I have seen no ads on your site, so I click the back browser button and leave.
IF you had an ad above the fold, near the paragraphs with that bridge location and the ad had a title of "longest bridge in the world". Odds are I will click on it. It sounds interesting and I will pop on over to that site just to see what bridge that is. Sadly, I am more likely to read their entire article, than I am to read yours. I knew some facts about the bridge you wrote about, I know nothing about the bridge in the ad.
So, why are you waiting to the end of the article to show ads to those few who will actually read that entire article?
Why do you think "above the fold" planning is so critical? It is because most of us do not scroll down. We find we want upon load. If we don't, we bounce. This is supported by countless marketing research programs designed to identify visitor habits. Yes, some will read the entire article. But, as soon as you use the term "some" you have reduced your CTR upon page load. Already a great percentage are guaranteed not to click.
When the ad(s) are seen upon load, 100% of the visitors see them. You have the maximum CTR possible at that point, in theory, 100%. From there, you begin to reduce the CTR because some arrived my mistake, for one reason or another. Now, consider, those who arrived by mistake, will never see that ad at the bottom of your article, which may in fact hold information on another site that DOES have what they were looking for. You just lost that click.
This follows tried and true brick and mortar marketing. If I bought 1,000 cases of a specific sneaker, and I really want to move them out in a hurry, not only are they going to be shelves by size, also by style, at the main aisle into the shoe department AND at the main entrance into my store where I am guaranteed EVERY customer will see them. If I don't want to see them in a hurry, I put then in the shoe department by style and leave it at that. With brick and mortar, the odds are high the customer will return again and again. Not so on the internet. You have to assume, though it is not always the case, you have ONE shot at that customer. What a shame to not have that ad where each visitor is guaranteed to see it.
It is a mistake to design a page and the entire site for the way YOU surf the web. We design for the masses. When we don't, we have failed. When Adsense is involved, you are looking at a scenario ripe for 'smart pricing' that will have you eventually posting about how your earnings keep going further and further down.
In answer to the question, "who wants to immediately click on an ad right after the page loads?". I can give you tons of responses, though I will give just some of the more popular reasons. It is the person who has suddenly realized after viewing your template that they have been to your site already and you did not have what they were looking for. That is one of the unfortunate results of ranking highly in the search engine for too wide of a topic. You are proud to be #1 for that one-word keyword, but still scratch your head wondering why your traffic is so high and CTR is so low.
It is the person who thought you would have a product for sale, and instead realizes you only have information about products. The visitor may have already read all the information on the product they need, they are now looking for the product, at the best possible price. This will nearly always just annoy the visitor. Something in your search listing lead the visitor to believe you had the product, and you don't. I can't tell you how many times that has happened to me.
It is the person who realizes the English on your site is second-rate and it will be painful to read your article. While you may be proud of your success at learning a second language, your site may look like a poor translation generated on that most popular free translation site. Those who speak English as a first language, will find it difficult to follow your train of thought. It is tedious reading, not something the average English visitor wants to bother with.
It is the person who sees the scroll bar on your page is only 30 pixels long, indicating the article is way too long, and they have neither the time nor the patience to sort through your article to find what they are looking for. If they are like myself, they will do a ctrl+F, automatically skip to the search results on your page for that query, read a line or two, then quickly scroll back up the top of the page, where of course, you have ensured there are no ads.
It is not uncommon for me to ctrl+f search on a page of normal length, so I can quickly get to what I am looking for. In fact, I do it a lot on WW, other forums, DIY sites, Wiki sites and news sites. If you have an informational site, you fall into that category.
If these people see an ad, above the fold, that looks like it might be a better option for them, they will likely click it. The exception would be landing on a MFA full of ads above the fold, which will only piss them off and get them clicking the back browser button. Of course, as most of us know, if the reason they want to leave is that tiny scroll bar on the right side of the page, the ads are likely not well-targeted any way. You have too much content, with too wide a topic, to draw finely tuned keywords for finely tuned ad topics.
While you might want to put one ad block at the end of the article, if you don't have at least one more above the fold, you are really missing out on major earnings. I hope that means you are running your 'business' out of your parent's garage that also serves as a place to rest your head.