JdeBPThe whole "init scripts are massive shell scripts" was always a bit misleading, although I _have_ seen several lengthy Mewburn rc scripts, especially in the networking parts of the system.
Mewburn rc was designed with a bunch of shell function helpers to cut down on common script code. Even van Smoorenburg rc, in a push to modernize in the early 2010s that was spurred on by the advent of systemd, gained a mechanism for much shorter scripts.