Why does it seem like being a Gym Leader is only a part-time profession for most leaders? Specially in the newer games, it seems like they only do Gym-leading in their spare time.

>Erika does flower arrengement
>Giovanni is a mobster
>Bugsy is a researcher
>Crasher Wake is a wrestler
>Pic related is a supermodel/idol
>Skyla is a pilot
>Drayden is the mayor of an entire fucking city
>Ramos is a gardener.

Does being a Gym Leader not pay? Do they all have other jobs to afford the puzzles and contraptions in their gyms or what?