Calling CA a "failed state" is an opinion, unless one devises criteria for measuring state failure.
The did have fiscal problems in 2009, but largely have traversed that until COVID.
I personally would view a failed state as one technically bankrupt. Illinois comes to mind as a state with a really bad fiscal situation that gets ignored often as not.
But if you visit the state, people are still carrying on much as before.
If you visit CA, you drive around and stay in motels and see the sights and eat in restaurants etc. and it mostly seems pretty nice to me.