I would recommend Bazzite or Aurora/ Bluefin. Bluefin is Gnome, and Aurora is KDE.

Both Bazzite and Bluefin are very similar. Bazzite is gaming focused, and the other one is more general purpose, but you can use them interchangeably and also rebase from one to the other.

They are the poster childs of the uBlue project, which uses, modifies and redistributes Fedora Silverblue images.

They both are part of the Fedora Atomic family, which makes them nearly indestructible, convenient and secure.

They focus a lot on containerised workflows, e.g. Distrobox, Flatpak, Homebrew, and, as you mentioned, Nix. They all come pre-installed, and if they don’t work ootb (e.g. Nix), they are just one ujust command away.

I have used both over the past year and I couldn’t be more happy. Give them a try!

Go with Bazzite instead.

The Nvidia drivers come pre-bundled with your install and are baked into the image itself.
The good thing is, they won’t break, and if they should, you can just roll back to yesterday’s image by just rebooting. It’s extremely reliable and lets you just dive into your optimal gaming experience straight away.

Don’t use Manjaro. The dev team is very sketchy and it’s a very unreliable distro. If you really want Arch, for whatever reason, use EndeavourOS. I personally don’t like the rolling release model and find Fedora (Bazzite) just right. If I need something from the AUR, then I use Distrobox.

PopOS is too old for me, and isn’t evolving at all right now. I would skip it until Cosmic is ready.