The kernel is responsible for managing hardware and general low-level system operations. Anything that wants to do those things needs to get itself into kernel mode one way or another.

The typical way you do this is called a "driver" and no one thinks about them as being kernel code. Things like graphics cards and the like.

Things that want to do actions like monitor network traffic or filesystem activity system wide or in a lower level capacity than the normal tools provide also need to be kernel level.
In a security context, that specifically would include things that want to monitor raw packets rather than the parsed content that assumes the packet is well formed in a way that a malicious one might not be.

Cloudstrike does the same thing on Linux, and the typical tools for network management or advanced security are also either compiled in or loadable kernel modules.
It's easy to forget that ip/ebtables and selinux and friends are kernel level software frequently distributed as kernel modules, in the case of the firewalls, or compiled in with a special framework and not just user mode software.