Which is better is a matter opinion.
Firewalld uses a much more modern paradigm than ufw.
- Firewalld provides service-based abstractions. If you are coming from another modern firewall (or even WIndows firewall) it should be more familiar
- Firewalld supports zones. These zones also integrate with NetworkManager so you can seamlessly switch between zones as your network changes
It includes a pretty good default config out of the box. I would leave it alone unless you need to allow something else through the firewall for a specific need you have.
We never shipped with ufw.
https://discovery.endeavouros.com/applications/firewalld/2022/03/