Does it have a good catalog module? I use LR 99% for organization and only do basic touch up. My requirements for a replacement would be an excellent import/export/organizer and a decent raw converter.
This was entirely unusable for me. RawTherepee is only for RAW treatment/export. Digikam can only do photo organization. Now here's the kicker: the two won't talk. Metadata known and written by one is invisible to the other. Using Manjaro, Rapid Photo Downloader eventually started segfaulting on me.
I also tried Darktable which looked much better and much more like a Lightroom replacement, but didn't like it.
So back to Lightroom, and even Windows as a whole, it is for me.
One thing to keep in mind is that Manjaro, similar to Fedora, is bleeding edge. Things break sometimes when running Manjaro or Fedora. That's the nature of a cutting edge distro.
The good news is that things that break are often quickly fixed.