Counter-anecdote, I switched to systemd all the way back in 2012 on Arch, even before it was mandatory and way before it was in a state where other distros felt comfortable switching and I remember to this day that after I did the conversion and hit reboot, an absolute panic hit me, I was 110% sure the system won't boot afterward, just because of how drastic the change was to perform on a live system, (because simpler upgres than that broke my system before). Since Arch is rolling is not like a new release came with systemd, no, you just switched your live system over.

I remember being absolutely floored when after that relatively complex procedure, not only did the system boot, but it booted faster. I think I became a fan that day.