I take your points, but all of those reasons is exactly why I find it baffling that I'm not better at Halo than COD for example, because those things you mention are the things I'm better at than just pure aim.
I only use COD as an example to illustrate that I'm a capable FPS player, and disagree that it's mostly luck - not sure if that's what you meant or not, but that's not the topic of conversation / don't care to focus on that.
FWIW; I have always much preferred the longer TTK CODs, and love the ones people hated (i.e: the ones that weren't "boots on the ground"). After all, I'm an old as balls Quake/ UT99 / UT04 player before "verticality" was a word