icedterminal

I was going to post this exact reasoning but you beat me to it.

It’s an industry security standard. Not a defect. If you don’t agree with it, fork the software and modify it to suit your needs.

Some self hosted services refuse to work if you use a self signed certificate with your public facing IP. They only allow self signed certificates when using one of the handful of private addresses.

Some apps on mobile devices for the service you use won’t work unless a trusted certificate is used. A self signed certificate behind the scenes creates an error that isn’t handled and you can’t connect.

You lose the ability to have a proxy in front to handle abuse so your server is spared the headache. You need a domain to do this.

TLS.

While technically you can use TLS with a self signed certificate, it creates additional problems with a public facing service. Only recommended for internal services.