Sorry for the low-denominator comment.
They are writable and readable by most modern standard drives.
The claims I generally see is 100 years for standard storage, 1000 years for archival storage.
Nowadays on Linux you can very easily mount LTO tapes like any other drive using LTFS, so you don’t have to become some hyper-expert with tar.
I had to “repair” the first one I bought, but that literally ended up being fixed by tightening a screw on the SAS connector. The second one I bought worked out of the box.
https://www.nature.com/articles/s41586-025-10042-w
This project has continued at Microsoft for many years. Now they report progresses in density and writing speed.
At the rate things are going, that might just be enough to hold a Windows with Copilot installer. /s
So the density is already good enough.
The main problem is the cost of the lasers used for writing, which would have to be reduced for mass production. The second important problem is the writing speed, but there also the cost of the lasers is the main problem, as for a greater speed more lasers can be added.
Despite the current writing speed being similar to downloading files from an Internet source that throttles you, I would be quite happy to have such a device, even with its current level of performance, to avoid worrying about having to pay periodically for new HDDs or tape drives, in order to migrate data from the old HDDs or tape formats.