The complaints I have heard from military pilots are that shortages are caused mainly by toxic leadership and unattractive career path options. Combat pilots don't appreciate taking orders from careerists or "shoe clerks". And they don't want to get stuck in staff or management assignments for years just because the service needs a warm body to fill a slot. Plus the day-to-day administrative workload is high even when they're not flying. So, a lot of them in the O-3 to O-5 range just get burnt out and quit. Air Force leadership could fix those retention problems if they actually wanted to, and it wouldn't even be very expensive.