If some number of pilots are distributed over some amount of regionals. Some regionals fail due to shortage of pilots. There are the same number of PAX that want to fly. So, the other regionals hire those pilots and take over those planes. They try to fly those routes. And there still is a shortage of pilots. Repeat spiral downward.
What will happen, besides regionals failing is:
1. 50 seat lift being replaced by 76 seaters. Same number of seats, fewer pilots needed. 76 seat lift being replaced by 737/320. Same number of seats, fewer pilots needed.
2. Abandon small markets where only a few 50 seat planes fly. Expect those PAX to drive to a major airport.
3. Increase number of newbies to go into flying. This takes several years. Not going to solve 2022 or next few years’ shortages. Increased pay, cadet programs with airlines to pay for part of their costs.
4. Bring in some of the 76 seat regionals into the majors. Give the pilots seniority numbers. The 76 seat flights, of course, will pay less than 737/320, just like they pay less than the wide body.
It will likely be a combination of all of these. One thing that will not solve it is waving of one’s hands nor sticking one’s head in the sand. Even another black swan event just defers the inevitable, like we have just seen.