Exactly.
Remember when they brought Goldberg back the first time to take on Lesnar again? That feud was good enough in premise and execution for their talents (and in masking their deficiencies) that it didn’t need the belt… but Vince gave them the belt with it anyways, and arguably trashed the even better long term story between Jericho and KO in the fallout.
If Punk takes on *anyone* of the “Top Card” caliber at AEW, that's already a headline feud and doesn’t need the belt. Now, I know I’m high on Darby Allin, but I can understand if others aren’t, but if you can substitute in Jon Moxley or Jericho there, you’ll see what I’m saying; they don’t need the belt, they just need time to get their story together and build to their clash, and then have Punk established enough to begin another story and another feud.
Punk is someone who could believably hold the AEW Championship, and of he has a decent career, he probably should… but he doesn’t need it right now, and I feel like he’s someone you’d want to set the stage for before he takes it.