This is a useless draft, I am just curious about difficulty of implement another init on Debian.
sudo apt-get install runit-init
Modify line of file /etc/grub.d/10_linux as follows:
SUPPORTED_INITS="sysvinit:/lib/sysvinit/init systemd:/lib/systemd/systemd upstart:/sbin/upstart runit:/sbin/runit"
Update grub2:
sudo update-grub2
Now you need to reboot the computer, so in Grub screen select “Advanced options for Debian GNU/Linux”, chose the option that have “(runit)“ at end.
You really can't remove systemd from Debian =$, but you can remove packages as possible:
sudo apt-get remove --purge systemd
Update grub2:
sudo update-grub2
You will remain only with libsystemd0 (almost on Debian 10).
I don't have any problem with the change… only the first boot took a lot of time, but the second one and following boots as normal… but is more slow than systemd in general speaking.