Part of Yayoi's backstory is that her family is not well off and as such she has to do all sorts of extra part-time jobs to make up for it. Also every other case where somone's reaching under a vending machine on Danbooru (e.g. post #29412 , post #169246 ) the implication is that that person is desperate for the change dropped underneath.
I had this 'smart' vending machine near my house. The change slot is designed in such a way that the coins will always fly out, hit your leg and roll down to the bottom of the vending machine. In this area, everyone is too lazy to lie down like that to pick it up. I usually leave it there for a few eeks and take a few bucks worth of coins underneath lol
