Google receives 92.42% of US search results. If you want new customers or users to find you, there's no choice but to do as they say. Also see AMP and media publishers.
Now if you listen to the various whines of said competition, Google sure looks objectively better too, using extreme personalization to drive more relevant search results to their userbase.
There is no pressure there. If alternate search engines were subjectively (not even objectively!) better, people would switch overnight. After all, they are just a click away.
Have you tried Google search lately?
It is almost never the case in technology that the superior product wins. It's the first to market with a really killer product. It takes massive inertia to displace an incumbent, and Google managed it because search engines prior to it were nearly useless portals (Yahoo, AltaVista, AskJeeves, etc.)
The requirements and conditions to displace Google now are virtually impossible, and that's even before factoring in their massive data profiling advantage.