CrowdStrike’s Falcon software uses a special driver that allows it to run at a lower level than most apps so it can detect threats across a Windows system. Microsoft tried to restrict third parties from accessing the kernel in Windows Vista in 2006 but was met with pushback from cybersecurity vendors and EU regulators. However, Apple was able to lock down its macOS operating system in 2020 so that developers could no longer get access to the kernel.
Now, it looks like Microsoft wants to reopen the conversations around restricting kernel-level access inside Windows.
Enterprise level AVs are going to sit in the kernel so they can watch for anomalies in the OS. There are better EDRs out there than Crowdstrike, and virus definitions are an outdated way of detecting anamalous behavior anyway.