> I don’t want search results to depend on my choice of web technologies (see AMP), or commercial relations between search engine and third parties.
(I work at Google, but not on search).
My understanding is that AMP doesn't actually affect ranking. Performance affects ranking, and AMP affects performance. But so do many other things.
There's also a similar conversation about placement (the "carousel"), which isn't ranking exactly, and that is affected by web technologies, in that certain placements require certain types of structure in the underlying site (metadata, etc.). AMP is one, but not the only, way to achieve this.
> By “fair” I mean I want it to only depend on the content of the site.
This is a definition of fairness, but it's certainly not the only one, and it may not be the best one. As a user, I want my search results to be tailored to me, which means that your ranking would depend on third parties (my priors).
Like, as an alternative, Google could list all search results alphabetically by url, like a phone book. That's fair too. But probably worse. So discussions of fairness don't make sense, because there are tons of terrible but "fair" ranking strategies, and for basically any query, there's someone who thinks they should be higher and that the reason they aren't is that the system is unfair.
> or commercial relations between search engine and third parties.
Do you mean ad space, or something else?