one bit of relevant information to add to my comment:
The guy who wrote pulseaudio also designed systemd.
Since pipewire seems to get rave reviews, and pulseaudio grumbles... a natural train of thought would be - get the guy who wrote pipewire to take a stab at systemd.
As to specific systemd changes, I would love if someone:
- Make the systemd config files more intuitive. While the old /etc/init.d/foo files contained arguably too much logic, the systemd service files are stupid enough that logic frequently has to be pushed into (and hidden inside) a daemon.
change the awful directory structure/files/links to something more elegant and organized It's like they threw them all in one directory, and simultaneously sharded them across /etc /lib etc
status commands/journalctl/binary log files. ugh.
How has it absorbed so much into itself?
It's become a little like busybox - making an analogy here - where it absorbs tried-and-true utilities and replaces them with "good enough" that... isn't. One example might be NTP which does time sort of poorly. Yes ntp is crufty, but it does time extremely well.