I bought all my games for the Xbox 360 in the past. I feel I can get better deals on used games, and games which were on sale, or discounted because the game is older.
I’m mainly a PC gamer, so my Xbox usage is pretty much all about Game Pass since I’d usually just buy games on Steam. We keep Game Pass for the kiddo, and it’s great for a younger one who likes to jump between lots of games. Sometimes we do buy his favorites if they get removed from the service.
I mix it up. Game Pass is great for trying new Xbox games without spending too much, but if I really love it more, then I’ll buy it outrightly so I don’t lose access later.