[BorisTheBrave]

I think it is more complex in most dimensions, except for render pipeline and asset size. Physics engines are off the shelf, even in AAA games, they're not really where the bulk of time is spent coding. Not to mention all the games you described have fixed maps and no multiplayer.

Really, most of the budget of AAA is spent on art and level design. They have sophisticated tech, but often it is not on an unreachable level.