Agreed. I have a monthly donation automatically taken out of my account
Internet Archive is not immune to collapse of civilization. In fact, such kind of service would probably be the first to be abandoned in case of war or serious disaster. It also requires electricity and I don’t think that organization have it’s own power generation capable of running in autarky for centuries.
There will always be a lunatic who encoded his entire usb stick in a granite block somewhere to be found in a 1000 years from now.
And at the bottom of the stone it said: stone overflow.
You'll see in older cemeteries granite engraving is not that good at preserving info.
On the scale of millennia, I wouldn't be too worried; disasters happen to any storage medium, and even our knowledge of Greek and Roman society today comes from surprisingly few sources. I think the bigger concern is the near-term effect of something like an EMP event, the digital library of papyruses burning down.
Letters from 1000 years ago obviously have great historical value, but it's not like they're the only kind of record that exists. We still print books, newspapers, government edicts, contracts, invoices, and photographs. We still hang plaques.
In a 1000 years there will be PhDs specializing in just the analysis of Twitter during 2016.