It's a fuck load of work to make a game. It is kinda ridiculous to go to all that trouble then just stop after making 2 hours of gameplay, like 2 hours total without even a good sandbox.
Not that it's Steam's fault, but this is the same way of thinking that has led to big budget, story focused games getting padded with repetitive fetch quests and annoying collectibles that unlock progression.
Yes, it's a lot of work to make a game, but the only way to extend the play time of a story-focused single-player game without having to do even more work, is to water it down with low-effort filler content that reuses the expensive assets.
There are also orders of magnitude of difference in their staff levels and budgets. Both sides of the equation are relative. I don't know of any techniques for creating good content quickly and inexpensively that only work for small indies and not for large AAA studios.