You’d need to drain the swamp first. Highly talented professionals tend to avoid deeply unpleasant work situations, especially ones that play out in public view, and politics today has become a game that requires a nearly psychopathically strong stomach.
Plus for the Tories at least (and I don't think they're entirely alone here) central party office, the local associations and selection panels all combine to vet out all but the toadiest soundbite regurgitators from shortlists.
It's a bit chicken and egg though. Pay a sensible amount and you might attract more capable people.