Debian lets you switch and AFAIK it mostly works fine. They provide both sysvinit and runit as alternatives. Packages are only required to provide systemd units now, however a lot of core packages still provide sysvinit scripts, and Debian provides a package orphan-sysvinit-scripts that contains all the legacy sysvinit scripts that package maintianers have chosen to remove from their packages.
That’s just in the official repository, of course. Third-party repos can do whatever they want.
If you try to switch a distro that’s already using Systemd to some other init system, you’ll have so many broken things to fix!
Debian lets you switch and AFAIK it mostly works fine. They provide both sysvinit and runit as alternatives. Packages are only required to provide systemd units now, however a lot of core packages still provide sysvinit scripts, and Debian provides a package
orphan-sysvinit-scriptsthat contains all the legacy sysvinit scripts that package maintianers have chosen to remove from their packages.That’s just in the official repository, of course. Third-party repos can do whatever they want.