Look at new student/private/commercial/ATP certificates issued over the last decade. The pipeline of new pilots looks bleak right now which means airlines are going to try to hire as many qualified pilots as they can get their hands on.

The hiring at legacies over the last four years has turned the regionals from well staffed to train wrecks. And the hiring at legacies during that time is only enough to meet retirements plus minor growth. Legacy retirements alone require ~2000 new hires per year.

Let's not forget that all airlines - legacies, LCCs, and regionals are fishing from the same pond of pilot candidates. The legacies are able to offer better 'bait' (pay, QOL) than LCCs and regionals. This has already started killing the regionals. I expect the same to happen to LCCs, as I don't think that they can compete against the legacies for a smaller pilot pool.

We'll either see a huge surge in new pilot certificates which will meet demand for pilots or the LCCs will start having problems recruiting and retaining pilots within the next few years.