This is a modern times phenomenon. Back in the 90s i never heard a single soul saying they wished for games to be shorter. We had fewer games then and we wanted more play time out of them.
Today we have too many games to play. Everyone has huge backlogs that they need to get rid of. People buy games just to add them to their digital store account and never play them. If you told me this 30 years ago, i wouldn't believe it. So now we have huge collections of games we don't even really like. When you play a game you don't really like that much, just because you feel like you have to finish it, you wish it doesn't last long so you can clear the next one and so on.
Achievements/trophies and other stupid OCD bait crap also makes people want to do less enjoyable things in games just for the score. If you only want that score, you hope for whatever you need to do to earn it to last as less time as possible because you don't really enjoy it.
Modern gaming is also a much larger industry than before and there are a lot of non-gaming, casual people now playing them. A lot more people with shorter attention spans. A lot who see games as "interactive movies" and prefer cinematic games. And since movies are generally tiresome beyond the 2h mark, games can only hold their attention for a few more hours at best.
Modern gaming also has more adults who have jobs, kids, etc so they don't have enough free time to play games, meaning they prefer shorter games. But the best case scenario for them would be to be able to work less and have more free time to spend to things they actually enjoy, not to make those things shorter lived.
Personally, i wish for my job to be shorter and my favorite games to be longer. When i play a game that i enjoy, i want that enjoyment to last as long as possible. Who enjoys something and wishes "ok, i really love this, but i wish it would end now". Nobody really, unless they stop enjoying it. And that's not because it has more content, it's because the game itself stops being enjoyable so the extra content feels like padding.