Ngl i felt the same in the beginning, but he slowly grew on me. It's just part of his character yk? like how he dons the Devil facade, i feel like he also forces his voice to be deeper to match his mask. Plus, he's also implied to be trans ftm, so his voice could also be a reflection of that.
Additionally, I personally think that V's voice wouldn't suit Ronin, and vice versa. V's VA just sounds very serious and not the kind to mess around, whereas Ronin's VA perfectly suits his crazed and playful personality!
Though of course, you are entitled to your own opinion after all! I just hope i was able to give you more insight. <3