This is only true if you ignore the ~$100k out of pocket and half a decade of training that pilots need before they can even get hired at a regional. Pilots need to self-fund all their training until 250 hours at the earliest, which costs $50,000 at the low end. Even once you land a CFI job and are getting paid to fly, you're probably making $15-20/hr for a few more years while you build time and drown in paying back the loans you had to take out. The pilot could lose their medical (more stringent medicals than we have to hold) after sinking tens of thousands into training, or have an incident that makes them unhireable, and they'd still have to pay back all those loans despite having no chance of ever flying for a living. Compare this to a new trainee at the academy who's getting paid from day one of training and won't owe the FAA a cent if they quit or wash out. This person has very little skin in the game beyond having to live in Oklahoma for a few months, and they're even being paid per diem while they're there.
Beyond all that, the current hiring boom at the airlines is almost unprecedented and is already starting to slow down. The airline industry is massively cyclical and there's no way of knowing when the merry-go-round will stop suddenly and leave a lot of people out in the cold. Ask someone who entered the industry after 9/11, or who had to take a 60% pay cut and lose all their seniority when their airline closed in 2009. I'm not gonna get into which job is harder or more prestigious or whatever, but you literally can't compare a government job with no experience required and paid training to a private-sector job that requires half a decade of self-funded training.
