3) you're pulling up irrelevant comparisons that dont make sense.
There is no reason for mihawk to exist if not for him to be zoro's final challenge. The fight doesn't have to be epilogue for mihawk to be zoro's final fight. The fights signifies zoro achieving his dream since zoro only associates WSS with mihawk and if that doesn't happen, the whole premise of SH journey to follow their dreams is bullshit.
Venus being a swordman coming after mihawk shits on zoro.