I see, that’s interesting. Well glad that it’s not hard to switch away from systemd on Debian for those who want it—although I still think if you don’t want systemd you should just pick another distro, given that the Debian installer doesn’t let you pick another init.

On Debian you can use both sysvinit and openrc

Huh really? Then why does Devuan exist? (I don’t use Debian for context)

I use Alpine for servers because I like its simplicity. Not in terms of computational power requirements, just in terms of user experience.

Alpine is an interesting choice for hosting

I’d say servers are one of the main uses of Alpine, second to containers. It would be a much more unusual choice for a desktop OS.

Alpine already uses OpenRC. There’s no option to use systemd with Alpine.

Popular alternatives include runit (which Void uses), OpenRC (Gentoo and Alpine), s6, sysVinit, dinit. The suckless people have also written some suckless inits—I think one of them’s called sinit.

So what are the alternatives that work with both Alpine and Debian?

None. On Alpine you can only use OpenRC and on Debian you can only use systemd. Most distros don’t let you change out the init system. If you want systemdless Debian look into Devuan.

Judging from this post, I would say you should not be looking to change out your init system as, no disrespect intended, but you really don’t seem to know what you’re talking about. You don’t even know what init systems your operating systems (Alpine and Debian) are using, let alone the details of different init systems.

Some people have strong opinions about init systems. They are nerds with reasons behind those opinions. You don’t seem to have many reasons and you don’t seem to be particularly invested in the debate. I would say it’s not worth your time to change operating system (which is what you would need to do to change your init) just because you heard vaguely that systemd is bad. If you reach a point where init system matters to you, then you won’t need to be asking the questions you’re asking in the OP.