FOS: Stands for “Free Operating System” as an inclusive term. Includes GNU/Linux, NonGNU/Linux, *BSD that are meant to liberate ones computing.
I’ll start, I use Linux Mint on my laptop that I use for work daily. It uses the latest Xanmod linux kernel and flatpaks for apps with GNU Guix providing everything else.
I recommend you watch this video, it goes over why the change was made, it was actually more about pragmatism and very less about “FOSS Purity”
Fedora is a very nice distro, definitely one the definitive leaders in the GNU/Linux space, so many new technologies like Pipewire and Wayland are pioneered in Fedora. I wish more distros were like Fedora and less like Ubuntu.