In the short term any rapidly growing organization benefits from the rather large percentage of people at the low end of the scale. PreCOVID early retirements some of the legacies would have had 6-7% of their pilots hitting mandatory retirement annually and will soon be back to that. The average guy/gal there is well over 12 years tenure. PreCOVID NK and F9 were growing 15% per year. By definition that means half your pilots have less than five years tenure and that at a lower rate. Even were the pay scales identical to legacy pay scales (and they aren’t) personnel costs at those airlines would still be less there.

For an even starker contrast look at Breeze. With the exception of perhaps a handful of their pilots, pretty much everybody is on first year pay.

Over time if the airlines stop growing, contracts become similar, and pilot size eventually becomes static, that personnel advantage will eventually equalize, but the advantage will remain for at least a decade or two. NK was talking about hiring 400 pilots a year. It’ll be a DAMN long time before they are retiring anything like 400 pilots a year. Until they actually do hit a steady state (new hires approximately equaling retiring pilots) this advantage will persist.