If you could actually pay once to have a file stored forever, that would be useful. "Perpetual care" for data would be valuable. There are Filecoin people who will take your money to do that, but don't have the credibility.

Now, if Berenberg Bank (private bankers since 1590 and still a substantial bank) managed the funding for this, it might be credible. One of the things they do is handle money on the scale of centuries.

Kind of important to point out this isn't in and of itself saying they are incorrect or lying. A carrot farmer may promote the health benefit of vegetables without nefarious intent.