Comment by JKCalhoun

I've had files in Apple's iCloud for 14 years now (had to look that up) and they're still there. I have no reason to believe that they won't still be there after I am dead. Apple is a big company with a big reputation to protect.

I can't say the same for the smaller services.

I don't have any grandmothers still alive but would certainly suggest iCloud for all family members.

(But, FWIW, I copy down everything from iCloud annually and store on a portable 1TB drive to have my own cloud-backup.)