If you updated to macOS Catalina 10.15.4 recently, you may have seen a warning message about kernel extensions. That’s because Apple is deprecating them in macOS 10.16.
The message refers to “legacy system extensions” and says they “aren’t as secure or reliable as modern alternatives.” Apple is replacing them with an Endpoint Security Framework. In a support page Apple mentions the change:
In 2019, Apple informed developers that macOS Catalina will be the last macOS to fully support legacy system extensions, and we’ve been working with developers to transition their software. By moving beyond these extensions, developers are helping to further modernize the Mac, improve its security and reliability, and enable more user-friendly software distribution methods. A final transition date has not yet been set.
The move is meant to increase user security because the kernel is a sensitive part of the operating system that controls everything else. Keeping third-party apps out of this area is a good thing.