People will continue using Bitcoin just because it's the standard. If it was just about convenience, then most crypto-to-crypto pairs would use Ethereum since it has a fiat on-ramp, is large enough and has relatively fast confirmations (I say relatively fast due to slowdown post Crypto Kitties). As is, Ethereum is used a decent amount but nowhere near as much. Without taking the Bitcoin brand, Bitcoin Cash won't become the predominant crypto-to-crypto pair currency. And to take the Bitcoin brand would require a LOT of changes to occur which are highly improbable.