glsimo cpma is pretty terrible in comparison if you want to look at skill because at the highest levels it just boils down to sneaking quickswitch rails which is hard but it's still just aiming - the mindgames really pale in comparison which to me is a more interesting form of skill
I sort of agree with you about but I think you're heavily oversimplifying it
on most maps you can do a lot to avoid rails and being able to counter-rail / avoid rails is actually an incredibly important skill that involves a lot of mindgames in itself.
That being said quickswitch rail is pretty bullshit especially on certain maps (aerowalk)
qw is also very punishing, much more so that other afps, which is why map knowledge is incredibly useful
also nothing has any dirt on broodwar, not even sc2 which I still think is way harder than almost everything except melee and there is still a clear difference between them.