Ignoring the lack of updates if the game is buggy, games back then were also more focused on quality and make gamers replay the game with unlockable features based on skills, not money. I can't count the number of times I played Metal Gear Solid games over and over to unlock new features playing the hardest difficulty and with handicap features, and also to find Easter eggs. Speaking of Easter eggs, you'd lose a number of hours exploring every nook and cranny finding them!
Depends a lot on the games for me. I can spend a lot of time on old games, if they were mechanically well made. But if the controls are clunky (like e.g. in old adventure games) I am out.
I think the early 3D era is the worst for this. We really had no idea how movement or cameras should work, and there was a lot of flailing trying to get it right, and people didn't even realise when it was right.
I was there 3000 years ago when Alien Resurrection came out and you used the left stick to walk and sidestep, and the right stick to pan and tilt, and it felt like utter unplayable madness.
That's one of the reasons Mario 64 still holds up. Despite being so early in 3D platforming it did a really good job with the controls and camera choices. It's a real mixed bag to go back to that era of gaming, Generation V, but I kinda like that. There wasn't preconceived notions of what 3D games should be so they tried everything.
I think everyone agrees that we leave early 3d games out of our nostalgia.