Marketers: The next wave of founders will be marketers, distribution is the new moat.
PMs: Taste is the moat, and its easier than ever to build the wrong thing. Now is the age of the PM.
Eng: You need systems thinking and technical chops to solve hard problems and wield agents effectively at scale. Engineers have more leverage than ever.
I suspect good people in each discipline will remain valuable and there isn't one role poised to become unicorns en masse.
I do think its good to be skilled at more than 1 discipline, but I am not sure any one of these disciplines has a leg up over the others in that regard