The proposition that there is not enough money, because of interest, is flawed.
The system will crash because governments spend more than their income. The music stops when nobody wants to lend more.
There is not enough money because of interest, this is a sound theory, since banks will never spend majority of the interest they receive, they just purchase more debt with their interest income, this is the main reason why banks just get larger and larger regardless of economy situation
Government can have positive income if they cut the welfare and raise the tax, but that government will be immediately voted out, so it is people who voted an unprofitable government