Only places I noticed you applying are the same places that everyone else likely has an app in.

Have a professional interview prep/mentor company review your apps/resume for things you missed. DAL scored your app twice and found mistakes both times- there's a decent chance the other places may be doing so as well.

Consider going to a U/LCC. It might show your career has stopped stagnating, and they could be a decent place to make a career out of if you don't make it to a Legacy/Cargo.