(Not familiar with Falco previously but I just did a little reading. Very familiar with osquery.)
Falco seems to expose much of the same information as osquery, however with a focus solely on k8s runtimes. Osquery can expose a lot of the same information (and much more), but across Windows, macOS, and Linux platforms. There is much less integration between osquery and any container runtime (though there are tables that work with various aspects of containers).