0/Near 0 interest is the end-game of fractional reserve banking. Consider the alternative: Rates climb back to 20%. You (and everyone else borrowing) now need to somehow collect an additional 20% (ignoring compounding and early payments) money each year. 1) that's not going to happen unless massive amounts of money are borrowed by lots of people 2) that money must move fast enough (and be continually reborrowed) to make it out to everyone who has an upcoming (very large) interest payment.

The banks are a serious drain on the system. They get to extract percentages from the economy year over year, while contributing nothing (except interest obligations).