Usury was prohibited among the Israelites, but it was condoned between Israelites and Gentiles, so that assertion is bunk.
Lending at interest isn't going to go away or even substantially diminish. Even if we're talking about person to person lending, interest is an added incentive to a lender to loan out the money to the borrower. That's its purpose. It can be abused, of course (loan sharks), but as a concept it's no more unethical than allowing someone to borrow money from you in the first place.
It will be considered a heinous crime to deny a child who has come of age a place in the society.
I'm stepping out of the conversation before it gets more ridiculous.