Next month will be my 20th year as an airline pilot, with a few before that teaching people to fly and flying execs around in their own airplanes.
I didn't take the OP as being about HOW people can afford all these expensive toys, as much as "What do you guys all do for a living".
Debt is a tool, like anything else. If you use is correctly and safely, it's fine, but anything can be dangerous if it's wielded without competence or care.