Mid's feats and portrayal has been far beneath shanks at every turn.
On screen fights: Shanks wifi diffs greenbull and stops an entire war causing blackbeard, akainu, all marines AND midhawk to turn around and run away. Also stopped the world's strongest creature from intervening in the war and sky split with Whitebeard. In the same arc Mid postpones a fight against vista, gets stopped by Jozu and gets dodged multiple times by haki-less luffy.
Place in the story: Shanks is the MC's inspiration for pirate king and hangs with the big boys in the new world, his bounty is 4 billion he is Roger's successor and currently going for the one piece which is a far more difficult path than the WSS. Midhawk hangs out in paradise and chases rookie pirates all the way to east blue. Gets chased from his own island by the marines. Despite being known as a 'marine hunter' his bounty is only 3.5 bill even with a yonko crew. Despite vivre cards claiming he's looking for a challenge he backs down from every challenge we've seen in the manga and only fights weaker opponents. Was also clearly afraid when Buggy announced he wanted the one piece. Zoro is his successor and is currently a million miles away from being on luffy's level. Also worth mentioning that he's on a meme level crew, whilst Shanks is a legitimate contender for one piece.
Future opponents: Shanks will most likely be fighting Luffy/Blackbeard and possibly some of the Gorosei. Midhawk will be fighting??? Possibly an admiral like Fujitora who are already confirmed far beneath yonko level and Zoro who will never be as strong as Luffy.
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The fact is Mid's entire hype train is dependent on Shanks and being a former rival to rookie Shanks, whilst Shanks' hype stands alone.