Yes, Devuan is more stable. It's not modified or forked, it's still Debian .deb files but with a different init system.
The difference is systemd is one thing to handle everything. The other inits are launched or initiated each time something thing starts on an individual basis.
I have heard that systemd has greatly improved, but a different init starts a new process ID for each separate program so if something locks or freezes, it affects that one inidividual init process. For systemd, which runs system wide to handle everything, if one program locks, systemd has to make adjusts for the whole system to fix the problem.
I also tried Artix, which is native Arch without systemd, and while it was still a rolling system like Arch, I found Artix to run smoother or lighter than Arch.
Some people find command line with systemd easier to do becase it is one centrslized control system, I say no, what you gain in ease of management you lose in optimal performance and precise control over each individual one, as opposed to systemd being a blanket system. I want Firefox running an isolated process from the one that Plasama desktop is running, each sith their own init started only when each one was started and not controlled by a shared resource.