Outside of PVP WoW doesn't require much thought for the majority of players. Rotations can be automated through things like TellMeWhen and other addons. Then there are addons to tell you what gear is better, when to move, etc. Simming for the most part is a 'solved problem'. And that is only if you want to raid. If you have no interest in raiding you'd be able to do everything by just pressing 2 buttons.
Diablo, you'd be in the top 1% if you just google builds and grind your way there. It's mostly a time thing. And when they had the Ah you could "buy you way to the top".
Starcraft is a pure pvp game so it's slightly different. Skill requirements are probably similar to something like Clash Royal. Although CR can pay to advance (cards). It still requires some general strategy and has a meta.