FreeBSD, OpenBSD, NetBSD, Illumos, etc. Chances are, you don't even need to tie yourself to the Linux kernel. Lots of OSes out there that don't inflict their users with systemd.
If you don't like systemd due to it being a lock-in, why on earth would you go with the BSD's who are all lock-in's with their respective implementations of lower-level plumbing which systemd is trying to standardize across Linux ?
The BSDs have far less lock-in with the default components than Linux distributions usually do. For example, I dislike the default syslog daemon, so, I disabled the default, and used my own. This involved adding two lines to /etc/rc.conf --
syslog_ng_enable="YES"
syslogd_enable="NO"
and that was it. Unlike systemd's way of doing it, the default syslog facility isn't started at all, doesn't run, period. Pretty much all the other low level services -- crond, dhcpd, ntpd, etc -- are the same way. This is one of the many failings as to how systemd operates. One should have reasonable defaults, but at the same time, if the defaults don't work, it should be easy to change them.
Well, journald is pretty much the one component of systemd that is very difficult to replace, but even so you can easily forward to another syslog daemon of your choice.
As for the rest, it's very much the same as with the BSD's, they all support their own versions of low level components and only them, and these can be changed by the user with compatible tools of their choice.