Check if your ISP uses CGNAT for IPv4. If so, then you're out of luck and IPv4 pretty forwarding will never work.
See if your router has an external IP in the CGNAT 100.64.0.0/10 range.
If you have IPv6 you can add a firewall rule to your router to allow the forwarding port through and at least have other IPv6 peers connect.
It's worth noting that the same applies when installing Windows.
Most people never do that either because it's already ~~bloated with malware~~ installed on the PC they buy.
Same with macOS, you buy the hardware with preinstalled software.
Gentoo enters the chat
No, your thinking of RHEL which is danish for "redhatsegregiouslicensingbullshit".
I'm reasonably sure it's the popping sound you make with your mouth oh ess.
I quite like "Pop!OS".
Or perhaps a play on IBM: OS/Pop!
Now that I think about it. It's just the !_ being beside each other that bugs me: OS_Pop! is cool.
I really don't like that underscore.
El Reg pulls no punches.
Welcome to the guild of calamitous intent!
I prefer my beer 93% alcohol free.
I use gnome at 4k and avoided fractional scaling by setting gnome to large text and increasing the ide's font sizes.
Nice crisp fonts, but annoying settings (but only set once).
... Or calling your aunt and having her yell things at you that she thinks might be on your Mum's shopping list.