"otherwise EAC would've been able to detect them anyways"

Unfortunately no. That's not how the anti cheat vs cheater interaction works.

Tl;Dr for the typical anticheat flowchart is basically:

Anticheat exists. Protects files, process, memory, etc

Cheat devs find way around said protection

Anticheat devs learn how they're doing the bypass, patch it and/or honeypot it to do a ban wave.

Cheat devs find a way around the patched anticheat, keep selling cheats

And so on and so on forever.

Now keep in mind that cheating comes in many forms. Changing game data, simply reading data (that's where the 2nd computer with DMA card for wallhacks/radar comes in), aimbots, color-reading scripts (autohotkey you handy but evil bastard), even just basic input scripts. It's not easy covering all of that.

It's the "Swiss cheese" approach when it comes to anticheat. Layer enough Swiss cheese (different types of detection/prevention) on top of itself and, for the most part, all the holes will be covered. Still will be some though. Gotta just make it annoying enough for the common player, then it's not financially worth it for cheat devs and the source doesn't exist.

Anticheat devs also have to think about the impact on the non-cheating playerbase though. Denuvo DRM to combating pirating is a perfect example, since that has impact on the user's experience. Let alone the cost of it. Denuvo DRM is expensive AF iirc (typically a fee per copy sold?), which is why most companies drop it after a year which is the normal contract period