Step-by-step reality.

you build the same base every time in team battles.
But here, at least, you plan it in real-time on a real game map, based on the events happening during the game, where sometimes you need to do things like instantly buying and selling, blocking units with buildings, maneuvering around them, keeping track of the location of buildings, combines, and so on, and make all decisions right now, not after ten minutes of deliberation.
And there, what, whoever builds the capital faster and gets better neutral spawns wins, after a hundred hours.