Was reading earlier this morning, and saw an opinion that really made sense to me:
AEW has been successful because the company is a babyface. It does things the fans want, books matches the fans want, and unlike WWE doesn't have a heel GM, or on camera people in power that are actively displaying bias, and trying to punish or hold down talent (whether actual or perceived).
When TK was doing those Impact commercials during Impact broadcasts and was low-key insulting Impact, we all thought it was funny and cute, but it was still very out of place, he really hasn't done anything like that before or since.