I stopped playing RTS entirely some years ago because of that.
I used to love RTS but...
1. Rushing is stupid, all RTS seemly suffer from allowing it even when devs attempt to curb that down, I remember in AOE for example people training on how to build towers on the enemy base in 2 minutes or how to win with villager rush. (also knew a guy that relentlessy tested ways to rise to the second age faster)
2. Singleplayer often the AI is super cheaty, after a while I got bored with that, because I couldn't use actual strategy to win, for example the match that made me realize that was when the last AI was on an island, I conquered the rest of the map, was careful in my usage of the market to stockpile all resources for myself and deny the AI... then whenever I attacked with the 200 unit limit, the AI defended itself successfully, after I got bored of hours stuck on this stalemate, I used cheats and found out the AI stripped the whole island bare but was still pumping units non-stop AND knew where I was going to attack, so they always had perfect defense.
3. Multiplayer is a matter of how fast you click and how good you are with pattern matching and some other training-related things, intelligence for example isn't that important, rote learning, time to practice, etc... that is.
So I concluded that basically multiplayer RTS is a huge timesink, and to me, unfun. And singleplayer RTS after the campaign is done is or too easy (because the AI is utterly dumb) or too hard (because the AI cheats), I never found out a difficulty I enjoyed playing against the AI.