Too statistically consistent to be natural.
LOL, randomness never looks natural.
I think my post above speaks volumes, in two respects. First off, if you need to question anything, it is the accuracy of SEMRush, Too many people put far too much trust in a service that from all accounts cannot be providing accurate measures of anything. How does SEMRush account for the fact that two people in two different locations see entirely different results. The bottom line is, it doesn't and as such the results are statistically meaningless.
My post above and my previous post, a few pages earlier in this thread (the one about the weather), demonstrate that Google is detecting high traffic and high revenue potential queries and adapting the search results to them, This is not only being done on the basis of location but it appears to be happening in real-time based on other factors such as current events or search volume. This fact alone would explain low conversion rate. Google can detect through some proxy metric when a search query will generate buying interest, it then ramps up ad serving on that query, thus diverting buyers away from the organic results. Meanwhile, for queries with little buying intent, no or few ads appear and the users continue to come to the your website. But these user have no intent to buy. While this will most directly impact organic results, it should also negative impact ads. If under "normal" conditions Google shows one or two ads those ads probably perform well, but if you are 1 of 4 ads squeezed between shopping and "also asked" and "tweets" and "knowledge", the CTR and likely the conversion rate on those ads should be negatively impacted.
@seomotionz
Its not SERP of search results rather than it is SERP of Ads.
It should not be SERP but SEAP => Search Engine Ads Page