MX, always based on latest Debian, is using sysVinit, but you can also boot with systemd if you want, it supports both. MX is pretty popular, simple, fast, Xfce by default, and very up to date on everything. I’m using it for 6 years now, on laptop, PC. Also maybe it’s me, but no flatpak, no snap, etc, not needed, for instance latest FF is a standard .deb