Psychologically, what causes certain professions and groups of people to have overly inflated egos despite masses of objective evidence they're losers/low ranked etc?

For example doormen are notorious for having huge egos/god complex's, despite being illiterate and service workers and working night shifts/risking being a victim of serious crime

Waiters are particular restaurants too have absurd egos despite literally being a boy who brings you a plate and serves you.

Some groups of unattractive women and also objectively poor people also appear to have massive egos.

It's got to be mental illness if you think you're above someone who is giving you orders then relaxing whilst you serve them right?

Lately I have even noticed cleaners walking around with their chests puffed out or not deferring to those they're cleaning up afterwards.

Objectively unattractive, and in particular MEN (short/poor/fat/ugly etc) checking themselves out in the mirror and taking selfies/posing... actual 1/10s