Native WebDAV mount support in Android would be handy. I use davx5 (https://github.com/bitfireAT/davx5-ose), but accessing files is a bit clunky.

I like WebDAV because it 'just works' with the mTLS infra I had already setup on my homelab for access from the outside world.

I use sftpgo (https://sftpgo.com/) on the server side.