This is all my opinion, I dont want to pretend that Im some big shot MS/SONY executive "know it all" as some others do over here
Gamepass is ((( at is current state ))) an utopian unsustainable business model in this industry, giving AAA first party and some third party day one releases for dirty cheap, is a model that even ((( IF ))) it worked can only be sustained by MS and their deep pockets, XBOX division could not alone carry-on as cant nintendo or sony, so is a "trojan horse" model implemented to cannibalize the other brands, buying the bigger publishers and studios in this industry one by one to keep their games "rent almost free" and push people away from the other brands, more specifically SONY as their final objective for market dominance, and after this is achieved who knows what gamepass and gaming would really became, not cheap forever i can guarantee you that. MS is a monopolistic minded brand, always has and always will be.
Furthermore this "not sell only rent" business stimulate the current streaming theme "quantity over quality" as we are seeing oh so often with MS, with shit games been pumped out of the "gamepass game making machine" in ever more unfinished state and with just bad quality, none of the streaming "NETFLIX" services provide really AAA constant hollywood quality, is low budget shit after low budget shit, sprinkled with the occasional hit, but the feeling is quite different from a multi-million theater film.
So in resume, IMO, is an "Trojan Horse" unsustainable businesses that stimulate quantity over quality, creates a mentality that an AA or even an A game passing for AAA is ok because is "free" and also changes buying habits making people for obvious reasons dont buy their games, wich make developers lazy and uninspired because they have only to pumpout some shit that doesn't need to sell and only make the volume the platform needed for that time.
Didnt like gamepass inception and nothing that it did until now surprised me or changed my initial reaction to it, but it was OK, until MS decided to start buying off the industry.