He's definitely A- to B+ for this current era. How can you be C level and hold strength, power, or speed advantages over nearly every opponent you have, indeed over the majority of the division? That makes no logical sense. Not unbeatable, but definitely not C-level. Stop it
Taylor was severely over rated due to getting controversial decisions over a 40 year old Hopkins who could no longer fight a full 12 rounds while making 160. He then got a gift against both Wright and Spinks. I did think he beat Pavlik in their rematch though. He would lose to Golovkin, Jacobs, Canelo, Andrade, and Charlo if his best version fought them today.