Yes, if I really enjoyed the game and it's leaving the service, I might want to keep it in my collection. Has happened with Ninja Gaiden, for instance. I'll also buy the Yakuza games because I want to support more Japanese games on Xbox. I do not buy Microsoft first-party game anymore and a lot of other games that I've played but will not return to. Still, Game Pass as far as we know compensates developers and publishers fair and square, so I don't feel bad about playing their stuff on Game Pass.