I don’t think there is a problem with it. It’s a piece of software that people can choose to use if it fits their specific use case. It has a long list of features and abilities, and lots of people find it sufficient for what they want.
There are also a lot of people that don’t find it suitable for what they want and they can choose to not use systemd and use some other options.
I personally don’t use systemd. I have used it for a while, originally I used sys v for a long time, then arch adopted systemd, I tried to get used to it and understand it but never felt comfortable with it, so I moved to void Linux which uses runit plus other items to replace systemd, and I feel a lot more comfortable and happy with this.
You do your research and testing and find what fits your use case.


You don’t need separate disks for this to work. I have my main distro and a recovery one all in the same disk in different partitions, and no grub. It is called efi stub and it’s really easy to set up and use. You can have as many boot options as you want.