Hmmm, I would absolutely buy one of those if it also had a hardened case and a firm connection point for my real-world keychain. The use-case is a "my house burned down what next" backup, password-manager stuff and other details I might need before/without accessing any cloud-backup services.

I may need to read some of its files on a not-very trusted device, and I don't want to risk that device also tampering/trojan'ing other files, like backup copies of the software needed to decrypt the data files.

A simpler scenario might be a USB stick that I use for carrying files to be printed at the local library.