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!
Games back then were also typically made by two dudes: one programmer and one artist. Heck, the original doom was made by five dudes: two programmers, two artists and one designer. I wonder what kind of nes games could be made back then if they had AAA budget like modern games.
One of those programmers was John Carmack, who happens to be ridiculously talented, and actually revolutionized PC gaming multiple times throughout his career.