if you use docker, docker ignores ufw rules

I like firewalld. Its also used on many enterprise distros (RHEL, SLES).

But if you just have to open one port for something, just use what's installed on your distro.

How often are you going to be managing ports?

Just use any tool you like, all they do is fiddle with the Kernel's filter table.

IMO firewalld because it's going to be more portable knowledge.

OS is xubuntu 24.04

Ubuntu defaults to ufw. That, by itself, justifies the use of ufw in your case.

Network Filter Tables (NFT) is the current system. https://wiki.nftables.org/wiki-nftables/index.php/Main_Page

I found firewalld had so many options that it was a bit overwhelming at first, especially understanding how zones were actually meant to be used, and how each zone had a default handover for the unhandled traffic. But OpenSUSE has a GUI for it so I was able to make sense of it. UFW seemed pretty user friendly and atraight forward.

I like iptables + opensnitch

Iptables. Because in the end its iptables, so I learned it from the beginning „the right way“ and i am therefore not locked into one or another