As long as they charge 6 figures, there isn't a real pilot shortage. This is just the industry whining in the hope of finding a sucker (US taxpayers) to subsidize a training program for them.
In other words, all other things being equal, you can probably train a decent number of pilots from savings from not cancelling flights, without plucking tax payers or raising ticket prices.
And then they wonder why no-one is biting...
Why isn't there a shortage of corporate lawyers? Because they pay them very well.
The industry can figure out a way to get people through the system if they really want to. They can find a way to hire military pilots if they really want to.
Currently, you need 1,200 hours experience from a designated aviation college or 1,500 hours experience from GA.
I believe airlines will lobby Congress to halve the number of hours in the very near future as they get data on the massive pilot shortage.