I think that at the moment, Bitcoin Cash is not strong enough to replace Bitcoin, even it can not beat ETH. Bitcoin Cash came out about a couple of months ago, it was detached from the original Bitcoin series. Although its value is high, but when compared to its history of growth and speed of growth, I'm afraid it can not replace Bitcoin, at least for the next few years. However, in the distant future everything can happen, Bitcoin Cash may be the first, we don't know the future.