Usury to me implies that it's a predatory rate. Even with reasonable rates, being on the hook for a reasonable amount still means I'm now incentivized to keep my little corner of the world static, as well as simply slowing change down, which also forces change in the wrong places while the "right" change plays catch-up.
If you have a chain of A owing B $2k/mo and B owing C $2k/mo and so on from A to Z, then if A through Y's sectors all change, Y still needs to pay Z, meaning X needs to pay Y, mean W still needs to pay X, and so forth. Meaning that even though nobody's paying usury rates, nearly everyone is still heavily constrained in terms of how they can adapt to change. And so they're incentivized to push the world towards whatever scenario they planned for, not because they like that scenario a priori, but because that's what they planned for.
tl;dr Credit lets you play time arbitrage, which sets up bad incentives when things don't go according to plan.
It's proven that any interest rate above zero is destructive and predatory. Thus, there is no difference between usury and interest in terms of immorality. There's a reason that usury is prohibited in all three major religions (Islam, Judaism, and Christianity).
We shouldn't have chains of people owing money to each other, we've seen what happened in 2008. Prohibiting lending money with interest will not allow such chains to form.
If you have a chain of A owing B $2k/mo and B owing C $2k/mo and so on from A to Z, then if A through Y's sectors all change, Y still needs to pay Z, meaning X needs to pay Y, mean W still needs to pay X, and so forth. Meaning that even though nobody's paying usury rates, nearly everyone is still heavily constrained in terms of how they can adapt to change. And so they're incentivized to push the world towards whatever scenario they planned for, not because they like that scenario a priori, but because that's what they planned for.
tl;dr Credit lets you play time arbitrage, which sets up bad incentives when things don't go according to plan.