They are confident without competence.
The late Leonard Nimoy said to the Star Trek convention fans who surrounded him and asked deep questions about philosophy and religious matters, he could only give answers as a normal actor who played a role and read lines from a writer's script. They still clamored for more.
“...They are confident without competence. ...”
And that’s an inverse relationship!
The more confidence they exude (usually loudly!) the least competence in the subject they actually have!