I found this article The Google Squeeze via Hacker News. I found it an interesting read.
It shows how Google Search’s Hotel Module is making it even harder for Online Travel Agent companies not to be in business with Google. Just Search Engine Optimizing (SEO) your site is not enough, because the adds and Hotel Module are shown before the regular results. The graphic showing the search results on a phone paints a clear picture.
I get the pictures this is part of a larger trend that is still ongoing. If you want to keep in the top of Google Search results, you have to keep up with new requirements and technologies.
(Personally I mostly use the European search engine Qwant)