EFT uses battleye. Most commercial anti cheats have had a kernel component for many years because cheaters moved there, anti cheats just followed them out of necessity. Valve VAC being one of the few exceptions, but its practically useless as an anti cheat. Vanguard is better because they designed the game with anti cheating in mind, not just slapping it on at the end as an afterthought. And it protects against certain cheats loaded at boot which other kernel based anti cheat don't protect against.

Unless you use multiple users on Windows a user space anticheat (or anything you run) can already read all your files and even memory of other processes (Windows provides an API for this), putting it in kernel adds the ability to do so for the other users. Invasiveness isn't really that good of an argument as normal software can already do so much.

One difference between EAC and Vanguard is that the latter needs to be loaded on boot, so you need to reboot every time you want to play if you don't want to have it running all the time (which is a common use-case since it has a history of interfering with legitimate programs).

Remember having to install "Cheating-Death" to get on some CS 1.x servers? Always wondered what it even did to your computer.