The problem people have with it is complexity or personal. You can run your linux kernel with init=/bin/bash and .... well, you've got a shell! A minimal init

The problem people have with it is complexity or personal. You can run your linux kernel with init=/bin/bash and .... well, you've got a shell! A minimal init system can be a shell script that starts some services. Job done. That has historically been the way to do it. There are also several other init systems that are native code based. Systemd is at the other end of the spectrum. It will setup cgroups and resource limits, syslog sockets per service, supervise services, support socket activation etc. etc. And that's without looking at timesyncd, resolved, networkd and a whole set of other systemd tools. I personally find it to be rather low complexity for what it offers, but it has a higher baseline complexity, so be prepared to learn along. And finally.... The maintainer is a rather controversial personal of pulseaudio fame.