That's what I was typically doing too. Only once every couple years was I buying a game near release for near full price. I almost certainly wouldn't have tried The Forgotten City if it weren't free, but it was one of the most impactful experiences I've had in gaming.

Idk about game pass, but stuff seems to stay on PS for a pretty long time. Once I caught up with a lot of what I cared about that was older to the catalog, I stopped thinking about when things might leave the service. The biggest shit seems to stay for a year or longer. If I'm still on one game for over a year, I should just buy that game and cancel the service lol.