I’ve been running Ubuntu on most of mine for a while now, but I go back to Raspbian now and then for the hardware support (graphics, in particular, are a bit of a pain, but I’ve also had issues with the built-in Wi-Fi). My “lab” Pi 4 is on Raspbian also because I like noodling in Mathematica (which I don’t think you can get in ARM64 at all for any distro).
It would be awesome to have a decent ARM64 SBC with a good GPU (able to drive 2 4K monitors and run Firefox/VS Code). Any recommendations from the non-Pi crowd?