Systemd is umbrella project for many software components, one of which is pid1 init. Almost all of the components are optional and many of them integrate through well-defined interfaces.
> Also, it has 1.2 million lines of code. It's massive for an init system. It increases the chance of potential bugs which can be exploited.
You're willfully conflating the systemd project repository with the init system.
I use systemd the init system, but in-tree components like resolved and networkd have never run on any of my machines.
Surely you can understand that a monorepo with code reuse across myriad components has its advantages, and that systemd the init system can be just a subset of that tree.
One can argue the systemd project is simply following in the Linux kernel's footsteps here. It too is a monorepo chock full of all kernel functionality one might ever need, with the expectation that use cases will pick and choose what snowflake suits them best.
> One can argue the systemd project is simply following in the Linux kernel's footsteps here. It too is a monorepo chock full of all kernel functionality one might ever need, with the expectation that use cases will pick and choose what snowflake suits them best.
Linux is openly a monolithic kernel that builds everything in one tree. Are you sure that's the analogy you want to pick?
Also, it has 1.2 million lines of code. It's massive for an init system. It increases the chance of potential bugs which can be exploited.