When ran from the terminal, the following error is given.
keepassxc: error while loading shared libraries: libbotan-3.so.4: cannot open shared object file: No such file or directory
Most likely was that a dependency was updated and Keepassxc wasn't updated with it.
Well spotted! Downgrading the package "botan" from 3.5.0-1 to 3.4.0-2 fixes this error and keepassxc launches as expected. It looks like there is already an updated version of keepassxc in the Arch "extra" repository for an alternative approach if you preferred to stay with the newer botan version, but I didn't try that, and the Artix keepassxc is probably going to be updated within the day judging from previous similar situations.
Indeed, the version in "extra" does work and am using it with my Artix install
Keepassxc was updated at some point between my post and now. It now works again, marking as solved.