Have we seen Kylo have a proper bout without handicaps against anyone worth a dime? He was hurt when he faced Rey in TFA and still managed to toy with Finn easily. He got passively ragged by Snoke, but that doesn't mean he entirely lacks the defenses he needs against Force Powers. He was entirely tricked by Luke's illusion but it wasn't really a straight fight.
Dooku held his ground vs Yoda and manhandled Kenobi. He's too experienced as a duelist and has the superior force powers.