Magisk is a complete platform that focuses on hiding "unauthorized" modifications from the rest of the system. You can add any mods as a virtual overlay, it supports plugins etc. Root is only one of its benefits.
Just plug it in. If it doesn't work, unplug it and plug it in again. You might have to repeat this 1023 times before the system is successfully rooted.
Here are things I'm currently using root for on LineageOS:
System-wide adblocking (hosts file with Adaway). Yes, there's DNS-based adblocking, but sometimes that can be slow or not play nice with public wifi networks.
Battery management. I use AccA to limit my battery capacity and charge rate to keep it from wearing out. I might not care as much if the battery was easy to replace.
File management, as there's an increasing amount of the filesystem blocked off without it.
Fair, but I guess my point was I haven't personally needed those things in some time. At least, not enough to warrant exposing myself to vulnerability like before. Ad blocking especially, since you can do that via VPN or by using your VPN slot if you don't want to use something like pihole. App + data backups are built into many custom roms as well, including the one I use (graphene).
Magisk had some incompatibility issues with lsposed-zygisk, which nearly resulted in losing my phone in a permanent bootloop, but I fixed it by flashing some images.
I now use Apatch on my Mi 10, running xiaomi.eu HyperOS 1
PS. I even tried KSU, by compiling a kernel for my phone after watching a ~40minute video on Portuguese with english automated subtitles, lol. Apatch has a much smoother procedure than that and kinda has the benefits of KSU.