If someone actually paid that small of a fee in BTC for several million USD, they would risk far more of their transaction being lost due to volatility during t

If someone actually paid that small of a fee in BTC for several million USD, they would risk far more of their transaction being lost due to volatility during the multi-hour long transaction. Anyone holding that much BTC, and facilitating that type of transaction will likely be subject to some form of regulatory scrutiny, sooner or later.