Auto-deleting messages and decentralization are an incorrect fit. Don’t enforce memory policy centrally. The edges know their context best.

To me, decentralization means two parties work out how to trust each other directly, sans intermediary. Unless read access to self-destructing data is controlled and limited by a trusted 3rd party, access can’t be revoked. Choosing that 3rd party usually means centralization.

They’re not decentralized and limit what they allow so they can’t abuse parties that rely on them. But unless you’re just gifting bitcoin or doing a crypto swap, there’s usually a parallel off chain transaction between parties that requires trust. Similar kind of trust happens when I send someone information.