I have a copy of a handwritten family tree and other notes written by great-grandmothers, cousins, and great aunts, some of which survived close to 100 years. If they had computers back then, I doubt any of the data would be available now. The photo books I have shared with relatives contains copies of these letters and charts and family photos, and even if half of them are destroyed or lost in the next 50 years, the remainder will survive, hopefully for much longer.

It amazes me how much faith other genealogists have in cloud storage or paid services like Ancestry, owned for the past 10+ years by a series of profit-focused private equity firms. Policies change (for PE's benefit), subscriptions lapse, people delete accounts, or online services get shut down, as some Ancestry users discovered the hard way:

https://slate.com/technology/2015/04/myfamily-shuttered-ance...

Another problem with these services: Even though I can share a link to an online tree or a shared cloud folder, more than half of the recipients hate to deal with them because they are forced to learn a new UI or get prompted to death to sign up for a paid service they don't need. The other half eventually forget the links or the information that was in them. Paper or books is the only proven long-term storage medium for genealogy data.