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!
I do miss manuals though.
The appetizer before the main course.
I think you can probably still get them for some modern games that were crafted with passion, through special editions and box sets. I think that the standard store edition of Total War: Warhammer actually came with a manual as well as a novella, and this was coincidentally the last physical copy of a game I bought.