You can email or hand out physical copies on usb would be one use case where server auth can't compete.

Aren't existing encryption tools more flexible for sending out copies via those methods? e.g. by making more cipher suites available? Or by allowing you to encrypt with the intended recipients' public keys, so you don't need to worry about distributing the passphrase securely? And might allow better integration with password managers, as the OS would recognise the files as being encrypted?

Supposedly browsers are more ubiquitous on the recipient side than whatever other tools you might use.

I was thinking of editing my comment to add "Or be able to support filetypes other than HTML", but I suppose in our glorious "everything is the browser" future, filetypes other than HTML are as anachronistic as 8" floppy disks.

Sigh.

FWIW, you can use data URLs to include any type of file in your HTML, and with <a download='filename' href='data:…'> browsers will allow you to save the file.

How do you use that on something like GitHub pages?

Turns out when you give up the work of hosting your up stuff, you also give up some of the benefits from doing so.

Which is why a project that returns some of those benefits is genuinely cool and useful.

And even can give benefits by storing it encrypted at rest.