"But if you don't have enough money in the bank, then the bank charges you. So it's actually more expensive to be poor than it is to be rich, and the richer you are, the faster you become richer."

Not only banking, everything is more expensive, when you are poor.

Miss a payment, because the money was gone before the end of month? You still have to pay it fully, plus fees.

Can only afford a old car? Pay more with repairs and tax.

You need money but have low bank reputation? Pay way higher interest rate - if you are lucky to even get the loan.

You get screwed over, but cannot afford a lawyer? Bad luck.

Etc. etc.