There is a small window in which to get hired at a mainline and have a good career. If you get hired in say 5 years you're going to be stuck behind guys most likely younger than you for the entire duration. Yes, there will be retirements and some people will get hired but not all will have good careers.
Like some people said you truly have to love flying because there are much better careers out there.
This is absolutely correct. Anyone starting flight training right now could be in for a very poor career.
People in right now could be in for a fairly decent one.
I would never start training now. Total waste of money.