Thing is, Linux used to be flexible. This because of some stuff it inherited from Unix about user space being made out of loosely coupled parts with solidified interfaces between them.

Meaning that it could accomodate both the latest and "greatest" coming out of the labs, and the tried and tested stuff that had been sitting in production for a decade.

systemd instead gloops it all into a lightly coupled shoggoth of a project that is chasing the future come hell or high water.