And frankly, that's not fun for a lot of people.
I don't want to win by clicking and mashing hotkeys like a schizophrenic on speed.
Yes, really good players click fast, but they also have impeccable resource management. The group I played with did run the obvious experiment: the best one of us was forced to play against the rest (one at a time) with an artificial click frequency limit. He felt like his abilities were greatly reduced, but he still beat everyone else quite easily.
At the bottom to upper mid level all you need to win is to figure out the macro game of building construction while also getting enough workers and units. With enough of that no micro is needed, just attack-moving into the enemy is more than enough.
Then at the upper mid level you're going to run into people who often don't build as effectively but they'll micro every unit or they'll be constantly doing raids when you don't expect it, scouting better than you and/or just understanding which units are better vs which so as to counter you.
From that point on it becomes much more of an effort to play the game because then you need to become better in all of those fields, while also becoming faster. But to be honest that point is probably 2/3rd's up the tree of all the people playing.
Not even at the lowest rankings are you permitted to ignore what your opponent is doing and focus on building workers and base facilities. StarCraft is infamous for the ability of anyone to sacrifice their economy to perform an early rush attack (most infamously with a ton of early zerglings).
To combat early rush attacks you need to be able to multitask: send out early scouts to see what your opponent is doing, if they have any hidden building on the map, how many workers they have, etc. You need to be able to do this while building your own workers, base facilities, and units for defence. This is the multitasking that so many struggle with and it’s required to be able to play at the most basic level!
Dealing with your opponent is a fact of every strategy game!
Keeping a scouting SCV alive in your opponent’s base while building more SCVs at home, building more barracks, building supply depots, killing the enemy scouting worker, and actually reading and correctly interpreting what your opponent is doing is non-trivial.