Airlines will have to increase their compensation to attract those pilots holding ATPs who work in other segments of industry (expats, corporate/frax/charter, those employed outside aviation, etc.) or go out of business. Then those businesses will have to increase their compensation to retain or recruit new talent.

Its this nifty thing called the "free market".

There will never be a lack of well-qualified pilots wanting to work at quality operators that offer suitable compensation and quality of life. Those companies that offer industry-lagging pay & QOL, well....they'll go the way of the dodo due to a lack of talent. It'll be short-term pain for some, for the greater good of the entire industry.