Its actually the exact opposite, hes very difficult at lower levels of play when your defence isnt that good. Kazuya doesnt have that many good universal tools to stop aggression.
DF2 is risky, df4 is highly - on block and m4 has abysmal range.
Once you have solid defence the gameplay just becomes enforcing your 50/50 and keepout at range with ewgf.
Kazuya really just gets simpler and simpler the higher levels you get to.
That isnt to say he is ever an easy character, but he really doesn't have to think that much in offence.
Most of his difficulty is in hands.
Mix up your 50/50 and ewgf timings with wavedash and enforce frames with 11.