I know a lot of BCHers have an ideal price scenario where BTC falls to zero and BCH moons forever. Part of me wants to see us pass them on the way up(just as they're popping champagne for the $100 transaction fees).
Agreed, BCH surpassing BTC on the way UP in a crypto bull market seems like a better scenario than BTC passing BCH on the way down in a crypto bear market.
BTC will dictate the market until it doesn't. BTC having the most trading volume, trading pairs and fiat onramps is not an immutable situation, though it will not be easy to overcome.
As BTC and ETH get slower and slower, traders will need an alternative for getting in and out of exchanges. They have no loyalty except to fiat dolla dolla bills. They'll use BCH.