The shift of Linux to systemd was a very similar experience to the decline of browser extensions. Yes, you can change how your computer works. But unless you're willing to put a lot of effort into maintaining those changes, the APIs you use will be cut out from under you and it'll be harder and harder to make your computer do what you wanted rather than what someone else thought it should do.
Just my own experience, but I've actually had more fun and more success using systemd to do funny stuff with my PC than with sysvinit. Can't speak to the other init systems though.
I've just reached the learned helplessness point where it feels like it's not worth learning anything because it's going to change again by the time I use it. Right now I've got a service that starts every boot that I stop manually each time because I can't figure out how to disable it; even if older init was "worse", it was "just" a shell script so I could do stuff like commenting out lines without having to go into the details.
I think your response kind of misses the point. It's not that you can't do things with systemD, it's that your previous hacks suddenly no longer work. The same will be true for your system-d stuff once redhad decides that they want something else.
The shift of Linux to systemd was a very similar experience to the decline of browser extensions. Yes, you can change how your computer works. But unless you're willing to put a lot of effort into maintaining those changes, the APIs you use will be cut out from under you and it'll be harder and harder to make your computer do what you wanted rather than what someone else thought it should do.