You don’t need to burn coins with OP_RETURN. You can send 0 to the OP_RETURN and just pay the fee to include the transaction. No coins are “burned” (removed from circulation), and your 80 bytes of data is on the blockchain forever.

There’s also this ordinals hack but don’t ask me how it works, it seems like a passing fad to me due to cheap fees, like satoshi dice was for example