But that seems to be the point, as the adverts are for more senior positions, it would appear there are enough Pilots to go around already.
One of the (many) problems within the industry is the slow promotion of lower grades to Sub Eng and Supervisor status.
Unfortunately, this also sometimes means people get promoted to a position they are incapable of doing just because they are short of people.
Some Sub Engineers do not take kindly to being told they are responsible for all the technical aspects of the system (which includes the maintenance logs and stores) and also can be required to run night shifts.
Some Supervisors are incapable of taking charge of themselves, never mind a team.
With promotion comes more money (which is what everyone wants) but with more money comes more responsibility and (supposedly) more experience to sort things when it does go wrong (or hoprfully to stop it going wrong in the first place).