- There are high health requirements to hold the job, which should be revisited
- The federally mandated retirement age is relatively low.
- Pay is not attractive
- Overall FAA funding is largely set by the finicky Congress, which swings between extreme austerity and moderate fiscal pragmatism
- Airports can supplement federal funding, but it's difficult to get someone that cares. The right port authorities would need to be elected, then raise rates at risk of airlines pushing back... only to improve the safety of their one airport (likely still taking the full PR/trust-hit if a tragedy happens at a different airport anyway)
- COVID19 led to a higher rate of people exiting the field (due to reduced labor demand + natural retirement), and few entering the field.
- Hiring/pay was not managed in alignment with the return of travel demand.
- These ATC articles have been circulating for a couple years now. That's probably dampened interest in these jobs.