Did you miss a required manual intervention on an update? A while ago there was an arch update that needed manual intervention cause of a dependency circle. Might be worth looking up the past year or so of manual intervention newsletter posts for Arch.

Last time I had a dependacy issue I was able to remove the conflicting package, update, then reinstall the package and it worked fine afterwards.

My own system was working great for a long while on an Arch flavour. But a bit ago HDR stopped working properly after an update and I just couldn't get it running right. Would display very dim.

Eventually gave up on my 2 year old install and went back to Tumbleweed.

I loved all the tinkering on Arch, but I just don't have it in me to do the tinkering anymore.