Why is usury considered a bad practice?

If I'm not wrong usury in its original biblical definition means charging **any amount** of money for lending money. So if you charge any percentage greater than zero as interest rate it must be a sin. Now my question is why is it considered a sin in Christianity? Does Christianity have a more technical and less non-religious answer for that? Like does usury hurt the economy of your country? Or what? I'm trying to understand if Christianity has an explanation to why usury is a bad practice and that's why I want a technical and non-religious answer.