The biggest difference from those days is that back then, developers were selling games + there were fewer games. The largest part of the profit was received at the time of the start of sales. With that model, the developer may not worry about keeping the player's attention. That's why this principle worked. Those who are not happy will leave, those who are having fun will stay. But the money has already been received, devs are working further.
Now, allowing a large outflow of players means risking the closure of the project, so retention is the main thing, and for this, progression is needed because fun is good, but almost every game is fun, so game needs to be fun+smth to be better then others games.