After having reinstalled the driver: Did you run sudo mkinitcpio -P before rebooting? If yes, were there any errors about kernel modules not being found?
Can you get hold of /var/log/Xorg.0.log when this error occurs? Perhaps this log can provide some more information.
Another possible interim solution: Kernel 5.4 is still supported. Can you try if it works with kernel 5.4?
Well, it’s embarassing… It took me 2 days to correctly read the systemctl logs and read that a line I added to my libinput config borked everything… Xorg could not start because of this. False alert the driver is good and I’m a moron.