One could even just use Arch or Debian. The different init packages are in the repositories and if you’re a level of user where your init system matters then doing it by hand shouldn’t be outside your skill sets.
There is Artix for Arch without Systemd but I find their hostile attitude toward Systemd annoying and immature. Their matrix group attracts political and off colour comments all the time. The mods try their best.
The Devuan community is more wholesome in my experience, where their goal seems to be about maintaining other options rather than just hating on Systemd.
There’s also Void, Gentoo, Venom (BSD style init), Hyperbola (Now a fork of openBSD starting this year), Parabola, Slackware. MX is probably the simplest to dive into.
Just a heads up for OP: Even though Parabola GNU/Linux-libre works to be init agnostic, and even though the OpenRC isos seem to be more frequently maintained, the systemd version is still the recommended version of the project (per the Parabola install guide).
I also agree with Ethanol about the Devuan community being more mature than the Artix community.
Again, Debian and Arch both have a variety of different inits in their repositories. You don’t actually have to leave Arch or Debian to run a different init system.