This might be specific to my tastes, but most of the games I play don't really have an "end" to playthroughs (and for the ones that do, it's very rare that I dedicate the time to play it start to finish without taking breaks to play other games, which usually drags playthroughs on for much longer than less casual players). And sometimes I just come back to old games years later for nostalgia.

Some of my most-played on Game Pass are Crusader Kings 3, ARK, Dragon Age, My Time at Portia, and No Man's Sky, which are basically what I go back to every time I resubscribe. But after getting up near a dozen months subscribed at $10/mo, I'm now really wishing I would have just dished out the cash earlier to buy the games instead, especially if I want to keep playing them over time. I'm very much in a sunk cost mindset though: "I've already paid to play the game so much, surely this month is the month I'll 'finish' it and get to stop paying, right? Therefore, I shouldn't pay full price to own it when I can just pay the $10..."

It's very much a digital Blockbuster all over again. There, too, I spent many more hundreds of dollars on repeatedly renting games that I should have just bought. But, like Blockbuster, Game Pass is really good for discovering new games because it's such a low cost to try anything in the library once.