

What you can expect when switching from a system management tool written for Linux to an init tool targetting the least common denominator of general Unix functionality?
Less functionality, less security, less information about the state the system is in, less reliable switching between states and a whole lot less of linux kernel features exposed to your use in convenient ways.
It’s not as if systemd was started to be complicated, the world got complicated. E.g. we used to just create all the device nodes in /dev statically during system installation. Then USB became a thing and supported so many different kinds of devices with thousands of potential ports to connect them to. They would not fit into the device node namespace! So we needed to make device nodes dynamic, which is also convenient.You do not have lots of device nodes that do not exist on your system and you no longer need to change system configuration when you plug your mouse into another port of your system.
Filesystems, security (often linux specific) features, everything is easy more complex (and more dynamic) today than it was when sysv init was a thing. That simple stuff was great when you had to power off your machine to change its available devices. It is less cool when you plug an USB-C cable into your laptop and want to use all the stuff that is now suddenly available.
Filesystem enable age verification in pretty much the same way as systemd does: You can optionally store a user’s birthday. That is such a ridiculous statement.
To be fair: None of the other inits cared for udev. None contributed or helped by providing features they wanted to improve udev. The systemd devs care for the lower level plumbing overall… and not just for the init system. So it is very natural for low level plumbing projects to land under the systemd umbrella today.
Systemds track record wrt. security flaws is actually pretty good. Not many went through the cracks,maven though some were indeed pretty ghastly. Hardly any was in the core functionality, most were in new code not widely used yet.
On the other hand, the service hardening that systemd enables has improved the overall security of a typical Linux system by quite a lot.