SC2 is great because it has that element, but it still demands that you balance an economy and protect workers and capture territory for resources and build production facilities and place them intelligently to manage unit movement in your base. However, due to the worker mechanic, your income is highly reliant on a steadily building number of workers until some ideal number for your particular intention (one base, two base, long map splitting game, etc). But workers rebuild rather slowly, so economic harass can be devastating. Workers are also weak shits that die super easily. So you end up having to closely watch and perfectly control your army and manage positioning for high ground and choke points and surface area and flanking, but simultaneously respond instantly to any threat to your workers, since an even army trade but losing 25 workers is probably a lost game. Often your armies will engage at the same time that some Dark Templar or Banshee or Banelings go for your workers. The intensity of having to control your units so you don't lose your army too one-sidedly, and protecting your workers so that you aren't left incapable of reinforcing your army, at the same time, is just something not offered by less multitask demanding games. Then you consider that often your workers at 2 or 3 bases may be attacked simultaneously AND there is an army coming at you. It's just a level of frantic intensity that you can't replicate in a game that doesn't demand a lot of multitasking.
I can't remember who said it best, but the ultimate resource in Starcraft is attention. How well you split your attention among the various demands, and how good you get at paying attention to multiple things at once, determines how good of a player you become. This dynamic just doesn't exist when you have very few things to pay attention to. You can appreciate good play by experiencing how hard it is to actually multitask. Humans are terrible at multitasking. Yet when you watch great players in action, they will do 3 prong attacks, and great players will amazingly defend 3 prong attacks with nearly instant reaction time. When I play, if a DT slipped into my worker line in a battle, I wouldn't notice. I'd win or lose my battle, go back to my base to make some more stuff, and notice I had no workers or money. A better player starts running his workers before the 1st one gets hit, even in the middle of controlling a battle. I can appreciate how amazing that is because it's so hard for me to think about more than 1 thing at a time, nevermind bounce around controlling different things second to second.