> you need like 2 lines of shell code in a BSDish rc.conf

... and then 223 lines of actual scripts, since those two lines in rc.conf merely enable/disable the services and do not denote how to actually invoke them. (Equivalently, the systemd people could say that they need just two symbolic links, one for enabling each service.)

    % wc -l /usr/local/etc/rc.d/nginx /etc/rc.d/sshd
         136 /usr/local/etc/rc.d/nginx
          87 /etc/rc.d/sshd
         223 total
    % 

... and of course another 2090 lines of shell function library for those shell scripts to rely upon.

    % wc -l /etc/rc.subr 
        2090 /etc/rc.subr
    % 

Mewburn rc is a fairly elegant system in comparison to van Smoorenburg rc (although it has its fair share of exceptions, sometimes quite bad ones) but it does not involve only 2 lines.