Fix the problem by paying professional wages and providing QOL... that will attract quality applicants.
The majors aren't having any problem attacting quality applicants, so raising pay there does nothing.
Regionals are paying more now than they ever did, yet they are having more trouble finding people now than they did back when they were paying 14K to FOs and 26K to CAs.
The problem is that the wage cuts at the majors have dis-incentivized (?) working for the airlines. People don't see the payoff at the other end, so they are not entering the field.
Regionals cannot afford to pay more, nor do they have any over control major airline pay, so they have done the only thing they can do: lower the barriers to entry.