Recently I made an upgrade of artix on my 10th gen intel laptop and ran into problems with SDDM; screen went black but I got mouse cursor. Also I got an error message in the /var/log/sddm.log, something like sddm-helper returned 11
I was able to login as a user and run startx though.
I found a lot of similar troubles but none of the hints helped me solve my problem so I figure I shall share:
On the Arch Intel wiki page (https://wiki.archlinux.org/index.php/Intel_graphics) is mentioned that the xf86-intel-video driver is no longer needed and I tried to remove it, along with the Intel graphics configuration I had in /etc/X11/xorg.conf.d/
This was the simple trick that made brought my laptop to live again.
Just in case you are looking to solve the same problem.
Cheers,
Erik
Thanks for troubleshooting and reporting.