I ran Artix for a while but went back to Arch. Maybe I missed something obvious, but it didn't seem like there was a nice way even to pacman -Syu on Artix because there were so many packages that were in both the Arch repositories and the Artix repositories. And you couldn't get away with only Artix repositories because there was so much they didn't have that the Arch repositories did have.
I assumed it was just that Artix kindof wasn't quite mature enough yet. But again, it's entirely possible I missed something obvious. I might well be interested to give Artix another try if so.
As far as I understand only Arch packages that depend on systemd need an Artix equivalent. You should be able to enable both Artix and Arch repos and everything should be fine, you should be able to run pacman -Syu without any problems. I never had problems in the last 3 years. If you tried it more than 3 years ago it might be a different story.