If an update is the cause of this, reinstalling won't solve it, you will get the same update on that install.
What was updated? Pacman log needed from that day/update. How far does it boot before you see this message? You get to the bootloader menu? Then remove
systemd...=0 set to 1, that way it will be visible if the kernel loads, what systemd shows. Or do you get to the login manager, and see the message after sddm?
Was the mirror up to date? Tried to make sure the update was complete?
For the above, most can be done by chrooting
If it was a kernel update (and you have the radeon card I suspect), adding
amdgpu.dc=0 to the kernel boot line might help.
What non-repo packages do you have, check with
pacman -Qm (while chrooted)? If that lists any kernel module, make sure to remove.