I agree with the lack of CA comments. It also points to lack of check airmen. Look how long new FOs are sitting waiting on OE. Some regionals are in the 5-8 week wait time. So it's not necessarily a hiring problem, it's a CA/CKA issue.

These are just my thoughts and I have 0 knowledge of the backdoor deals mainline carriers have with their respective regional carriers: Regionals can only pay so much before they get too expensive for their codeshare partners. Start throwing in company contributed 401k and some other benefits like soft pay items or higher credit trips for a better QOL and you might, might, see some retention. This may not even be possible since it's still a cost to the company, but just something rolling around in my head. But I truly believe bonuses are not where it's at.