Is this with the exact same traffic as 6 years ago?
Let's hope not. ;-)
The world changes, the economy changes, ad programs change. You need to stay on top of things, keep improving, keep tweaking, keep growing.
In the old days (6 years ago) Adsense came on the scene and was an instant hit with both publishers and advertisers. Things have changed over the years. They have improved their technology, both for the benefit of publishers and advertisers.
Is it the same as it was 6 years ago? Of course not. Nothing is. So you can't compare simply "traffic" from 6 years ago. You need to look at the big picture. Have you constantly improved your site every year? Are you pages more user friendly? Do your pages offer value to advertisers? Maybe 6 years ago that didn't matter, but now Google is adding more and more variables into the pricing algorithms. If your pages are helping convert ads to sales, you'll obviously make more than if they are not.
Does our traffic grow over the years? Of course, but that is not the driving force in our increased revenues. We keep pace with what advertisers are looking for.
As the market changes, not all sites and companies will fare the same. Some will find a bit of luck and fall into a profitable category, others will fall out of luck. Others will do well from hard work, others will fail no matter how hard they try. That is the way of the world.
From our perspective, 6 years later Google Adsense is still the top publisher program out there by a long shot.