There are types of time management which I think can still be interesting. For example, are you able to afford -- in the resources of time and attention -- optimally micro'ing this important fight? Or are you going to have to yolo it a bit so that you can do multi-task economic tasks at the same time?
Some (much?) of the problem is that (for better or worse) skilled players can and will squeeze the game to optimality in terms of win rate, and that tends to collapse viable tactical and strategic choices. Once those choices have been optimised (the game is largely "solved"), the main way to get better is by being faster, not by being smarter.