I'm mostly a happy systemd user. Unit files are much easier to work with and more consistent than init scripts, the faster bootup (at least on my arch and Ubuntu systems, maybe you could make Gentoo even more minimal with initscripts), and the container/isolation features won me over.
That said, I can understand the objection to software that would previously support BSD or macOS now only providing systemd units or depending on other parts of the systemd project that in turn depend on the init making at a pain for portability across unices. Or software like gnome taking up huge amounts of time for the BSDs to support.
Unit files are great. SystemD should have stayed there. But then it handles networking(including configuring network interfaces), and time synchronization, and name resolution, and the kitchen sink.
Even https://nosystemd.org/ mostly just lists bugs
After moving all my services from varius init systems to systemd, I'd never go back