Nobody said that we consider them usury. We're neither Jewish nor Muslim.

I picked the building of a major road with a bridge, to illustrate the sort of project that would be difficult to finance by private interest-bearing loans. In the near past, they were financed by the state and the money was simply pressed out of the populace through taxation or through cheap loans to the private builders that were supported by inflation.

That said, full-recourse loans (as opposed to something backed by collateral) are a form of indentured servitude, if they cannot easily discharge the debt. Mortgages (except the ones that allow you to walk away and leave the key) and US student loans are typical non-dischargeable, full-recourse loans.