Its similar to the CVS analogy given below, however I would liken it to Pulse Audio. We know we have needed to "fix" the audio subsystems for a while, and Pulse fixed a lot of problems but by the time it came along what were problems had moved on. Pulse ended up with other issues, and not actually doing everything we actually needed so it was eventually replaced with Pipewire.
I'm not sure if Systemd falls enough into the same pattern, but I'm sure something better will emerge in the next few years.