Playing as Law confirmed it for me. Technique types suck. A shame. Law was one of my favourites in PW3.
Playing as Carrot now though, and she's much much better.
I just tried Hawkins. He's not bad. His technique part is cursing foes with his regular attacks, then you press square/Y on it's own and something, I think depending on how many people cursed, falls from the sky. This ranges from a barrel that does little damage to meteorites that do high, AOE damage. His regular attacks do OK damage, but it's easy enough to curse large groups of people to make it work.
My problem is, the idea of a technique character is they're supposed to be complex, but super rewarding if played well. I've played Big Mom and Kaido, the only threat to them is the camera. I effectively just mash buttons and win, maybe avoid Kaido's combo that takes forever to finish. I legit doubt Law, Bege, or Hawkins can even come close to their level.