Apple clarifies policy: Only the latest OSes are fully patched

“Extended” support for macOS Catalina was dropped in September according to Wikipedia.

The same thing happened to macOS Mojave last year (and macOS High Sierra the year before that, and so on and so forth).

For now, people using macOS Big Sur and macOS Monterey don’t have anything to worry about. They will continue to receive critical security patches when necessary.