[pgodzin]

If they were paid $1M and could get more then they are still underpaid and there is sufficient demand.

There is no absolute number at which they are no longer underpaid, it is completely relative to how much demand there is and how much companies are willing to pay for that demand.

[viraptor]

If the airlines and pilots existed in isolation then maybe. If they were paid 1M, I'd think they're overpaid and the tickets should be cheaper instead. There definitely is a threshold compared to all other salaries / cost of living / economy where the pay would become irrational - regardless of demand.