DataDrake Casper [ 992.188] (EE) open /dev/dri/card0: No such file or directory So something is going on with the driver loading during boot. Have you changed any boot flags recently?
DataDrake Casper Can you run sudo clr-boot-manager update and tell me if it errors? It doesn't even look like the kernel tried to load the amdgpu driver :/
DataDrake Casper Running out of things to check. At this point I would run a sudo eopkg check to look for broken packages and maybe go so far as trying to directly start budgie-desktop from the command line to check for errors.
JohannPopper @Casper Hey, not to suggest the obvious, did you actually reboot the machine after running 'sudo clr-boot-manager update'? Because another person and I ran into what looks like the same problem and just running the update fixed the issue.