Behavioural interviews are extremely effective provided you do them properly. Running behavioural interviews properly is extremely difficult and takes legitimate skill and experience to orchestrate. It's not something you can pull off by simply following a few rote questions in an interview pack.
As a result, most behavioural interviews are ineffective and absolutely riddled with bias.
That's one of the reasons that they are best done by experienced HR personnel.
Good HR people are worth their weight in platinum. I used to work with one whose thumbs down became an automatic "no" from the team because we discovered that she was so good at reading people that everyone she didn't like inevitably threw off massive red flags in the rest of the interviews.
This is foolish. Anyone can have a bad day, including the clairvoyant HR. Don't build an interview panel around pleasing "that one gal"; that kind of situation happens enough by accident.
And if you have a bad day, tough. That's one job you won't be getting. No one ever said that life is fair.
No one is building a panel around pleasing anyone. If you have a member of your team who is particularly skilled in any area, it would be foolish to not take advantage of it.
As a result, most behavioural interviews are ineffective and absolutely riddled with bias.