I think it was a ZFS dev who complained he had to update 150 files to port ZFS to systemd. Simples?
And you have to love all them binary log files, with their dynamic and spontaneus api. Yes, everything is always new and exciting with systemD.
I use devuan. A debian fork with a choice of init systems (well, everything but systemD. ;) It took the dev/devs 2 years just to swap out/revert the init system.
Also, just learned devuan's website is JS and cookie free. https://www.devuan.org/
Edit: I will concede that systemD is great for a lot of people. I honestly wish them success. The work that goes in to building, maintaining, and using it, is substantial. It must be a boon for the economy and job creation.