All about self promotion
"Google’s search results page is both a “neutral” platform and a shop-window for its own services."
Neutral?!? Who can claim this with a straight face? Everything is slanted, optimized and filtered to the benefit of the search provider. Google, Bing, Yahoo, etc...they all do so. Ask yourself, why is it that when troubleshooting any Microsoft product, you use Google instead of Bing if you expect the the quickest path to a solution. Ask yourself why, if you are searching for pr0n imagery with all fitlering allegedly disabled, you favor Bing images instead of Google Images. Ask yourself why you closed that Yahoo Movie search and opted for Google's Movie search....was it the endless display of click bait ads?
They all monkey with the results to get your attention and maximize their revenue. Why do most of us keep going back to the Alphabet soup?