For photos or documents like wills I think the best long term storage solution is still physical prints in a shoebox. Yes, they'll fade slowly over time, but will still be viewable for decades, or even centuries if printed using pigment inks on archival papers.

Of course there's still a chance that physical prints can be lost, stolen or destroyed in a house fire. But I think overall that's statistically much less likely to happen than digital media becoming obsolete or unreadable, or data stored online being deleted because the original uploader stopped paying the storage bill or didn't arrange for transfer of their accounts after their death.