Some services run really good behind a reverse proxy on 443, but some others can really become an hassle… And sometimes just opening other ports would be easier than to try configuring everything to work through 443.
An example that comes to my mind is SSH, yeah you can use SSLH to forward requests coming from 443 to 22, but it’s so much easier to just leave 22 open…
Now, for SSH, if you have certificate authentication or a strong password, I think you can feel quite safe, but what about other random ports? What risks I’m exposing my server to if I open some of them when needed for a service? Is the effort of trying to pass everything through 443/80 worth it?
Everything you expose is fine until somebody finds a zero day.
Everything these days is being built from a ton of publically maintained packages. All it takes is for one of those packages to fall into the wrong hands and get updated which happens all the time.
If you’re going to expose web yourself, use anubus and fail2ban
Put everything that doesn’t absolutely need to be public open behind a VPN.
Keep all of your software updated, constant vigilance.