I’m so sorry you’re going through this - job hunting sucks and the rejections are horrible.

Further to Taleya’s comment, in my field jobs also get advertised even when someone has already been chosen, they just have to appear to be being ‘equitable’ employment-wise. Then, surprise surprise, the biggest suck or boss’s bestie lands the role.

Also, hiring managers are just people and some aren’t so great at their jobs, particularly when it comes to providing useful feedback or even being tactful with rejections.

Hugs and I hope you’re feeling a bit better soon