Modern games? Usually yes. I'm a trophy hunter, so the Platinum is always my goal...which requires finishing a game and doing everything it has to offer (in most cases). I finished Ghost Recon: Wildlands the other day, currently playing A Plague Tale: Innocence, probably Platting it today (definitely by tomorrow).
However, it really is the trophies that motivate me to do this. I have a bad habit with Switch games or retro games of getting pretty far and not finishing it. Like I played the GameCube version of Zelda: Wind Waker a little while back, got to the point where you need to collect the Tri-Force shards, and just....stopped. I was enjoying myself, but I haven't even looked at the game in months. Or more recently, playing Metroid Prime Remastered, I'm pretty much at the end, but decided to backtrack everywhere to get all the pickups so I could see the Good ending...got to about 80%, haven't touched the game in a couple of weeks. I haven't given up on it yet...but it's just strange I went from looking forward to playing it to just not playing it at all.