Comparing post timeskip powers with pre timeskips is silly, Armament Haki making your body black wasn't even a thing back then. Haki was barely fleshed out by Oda. By that logic Akainu didn't go all out either.
Akainu was using CoC and commanders were using CoA
There was even sky splitting going on
Why is it that Shanks lost to non commander teach and got blitzed by sea king??
Where did his CoO go?
Dude the fact that Mihawk is above current Zoro who low diffs Katakuri who was blitzing post time skip Luffy already shows how garbage your argument is.
Luffy also walked out alive against 3 admirals.
And post time skip Big Mom has worse anti feats than pre time skip mihawk.
Show me someone kinemmon blitzing and hurting Mihawk like they did with Kaido.