This NFT stuff still makes no sense to me. Is there anything about this ownership that would stop twitter deleting that tweet if they decided they wanted to? Is

This NFT stuff still makes no sense to me. Is there anything about this ownership that would stop twitter deleting that tweet if they decided they wanted to? Is there anything to stop Jack selling it again on another blockchain? I can't work out if it genuinely is crazy or if I'm just missing some fundamental part of why claimed ownership on a blockchain is worth $3m, beyond it being worth that because its what someone paid for it.