Thats a myth, app development is one of lowest-paying software niches. Many don't even earn enough to recover their $99 fee.
Sure, Apple hands out a huge pile of cash but almost all of it goes to King, SuperCell and other big corps.
I still make $1,000 to $2,000 a month from my old apps, without updating them.
I now make over $130k a year (salary + benefits) in my day job doing iOS development, in a city with one of the lowest large city cost of living in the U.S.
Apple just announced they've paid out over $70B to iOS App developers since the store opened. You don't have to be an owner of King or SuperCell to have gotten your share of that money.
But multiple studies have shown that only a select few make the big bucks:
https://techcrunch.com/2014/07/21/the-majority-of-todays-app...
Different worlds I guess...
this might not last, but you can always switch to android. unless mobile dies out completely, but that won't happen for a while