Hear, hear!

And yes, it is true that nearly all NFTs are on two commercial services, though they probably have a bunch of servers behind the scenes.

It's madness! At least tulips are pretty to look at.

EDIT: The current state of the ledger IS duplicated on all cryptocurrencies I know. Previous transactions are as you say only stored in backup. But as long as anything of the cryptocurrency remains, your transaction is safe but not any of the contents it refers to.

This isn't a particularly impressive feat though.