Step-by-step reality.

actually, RTS games are often more monotonous than TBS games, so...

RTS games have another problem: the pace of the game is faster, and the player needs to react immediately, within a couple of seconds, while the pace in TBS games is more relaxed. And in multiplayer, micro-control also plays a significant role, which is also a matter of personal preference. Of course, there are exceptions among RTS games, such as Majesty or Kohan II, where these elements are expressed to a much lesser extent, but there are far more counter-examples.