"rsync.net isn't a viable solution. For example you can't host images, videos, software updates, machine learning datasets or other large binaries and serve them over HTTP on the public internet."

Correct. We don't do these things and we never will.

When you 'nmap' an rsync.net storage array, you get:

22 TCP

... and that's it. There are no other services running, or offered. There are no interpreters in the environment. The filesystems are mounted noexec,nosuid.

We do one very simple thing and that's it.