Your understanding has a factual error; it's impossible for there to be a non-YB crvUSD-BTC LP. TLDR: YbBTC's revenue comes from the dynamic fee rates of Curve crypto AMM. If BTC's volatility is high enough, the fees generated from arbitrage trading exceed funding costs + rebalancing costs, resulting in positive returns. The revolutionary aspect of YB lies in creating an AMM LP structure that can fully hedge IL.