While I can understand the rationale behind it, I can't imagine this being used for anything that requires low latency requests. I imagine the flow would be so

While I can understand the rationale behind it, I can't imagine this being used for anything that requires low latency requests. I imagine the flow would be something like (correct me if I'm wrong) [client request] -> [backend returns an error]/[accepts the request and waits for payment] -> [client sends the money] -> [backend accepts the transaction] -> [backend returns the requested data]. All of this sounds like a huge bloat over the current API key/token system.