[rsync]

"The backend is done with... there's no backend! The data is directly on The Blockchain, fetched from the browser through a standard-ish API (Web3) provided by your wallet or a gateway."

Not stating this to be obnoxious, but to be clear - there is a back end for the web page that calls the data from the blockchain ... if (whoever) stops hosting that site or DNS is halted or the domain expires ...

[thepredestrian]

It is still on the blockchain. You just won't be able to see it -- or you can always throw up another page to display the data