Agree, systemd is not the last word in init systems. There are use-cases where linux/whatever is used to run a single system across a cluster of hosts. For thi

Agree, systemd is not the last word in init systems. There are use-cases where linux/whatever is used to run a single system across a cluster of hosts. For this, you need a scheduler to dispatch across a set of machines. There is room to debate whether init should happen at the system level (driven by OS tooling), or at the application level (not driven by OS tooling). Systemd is bound by single-host assumptions. Hence, systemd is either inadequate (OS tooling) or else too complicated (application driven). If you wanted to do something in the spirit of systemd (OS tooling), but which was suitable for clusters, the scheduling function would live as a consensus across a grid of hosts. Hosts would have a simple init that joined that consensus at boot and which acted as an agent for the init consensus. This would scale down to all the use-cases systemd currently covers - you could have a consensus of one.