At What Point Does Armed Robbery Become The Only Option?

A gang of 7-man robbers robbed my street last week, collecting phones and other valuables from more than 10 people. I learnt they even forced the victims to transfer money to a certain untraceable account. My question is, how did people become armed robbers? Like you resorted to doing armed robbery than any other legitimate hustle?God knows I have been in very terrible situations but resorting to armed robbery never crossed my mind for once. So why others?What about so many other things you could run legally to still earn money? Why armed robbery?