I don't necessarily feel satisfaction from completing games. I feel like most of the time I finish a game it's because I just want to finish it so I can move on to something else. The satisfaction I get from a video game is from the mechanics... how good it feels to play. If those mechanics can carry me through to the very end, then I'll play it until the very end. Otherwise, I'll maybe play it for a few hours and then drop off. That's how it's been with a lot of titles that otherwise are incredibly good, such as FF7 Remake, God of War, and Resident Evil 2. The gameplay wasn't geared closely enough to what I enjoyed for me to keep playing.

I think this might be why a lot of people these days play things like multiplayer and endless games (like roguelikes) a lot more often than single player, linear adventures. They enjoy the mechanics enough to continue playing and don't feel like finishing the game (if it had an ending) would bring them as much satisfaction as the gameplay itself does. I think this is why something like speedrunning or going for high scores is pretty popular too, because it means there is more to do than the definitive ending of a game which you garner less satisfaction from.