If somebody can’t put away a good retirement making $200k-$400k a year then something is amiss. ($500k for several at K4)
The LCC’s just recently started getting DC’s. I’d expect that the ACMI’s won’t be far behind.
Are they the big six? No.... but they are certainly respectable careers in their own right.
For many, living in base at an LCC or being home based ACMI beats commuting to a crashpad at a legacy. QOL has a value that varies from individual to individual.
YMMV