It Bitcoin Cash would have replace Bitcoin, it had happened in 2017 where people are complaining about Bitcoin huge transaction fees and slow confirmation times. Bitcoin Cash touted to be big blockers and as such very quick and could be the Bitcoin killer. But it didn't happened so I guess logic dictates that people will still stick with Bitcoin ecosystem even if there's competition. Besides, Segwit and LN has reduced dramatically the fees so I don't think that its a problem to Bitcoin network now. And if you are familiar with hashes, Bitcoin Cash Hash Rate Drops By 37 Percent in One Day: https://u.today/bitcoin-cash-hash-rate-drops-by-37-percent-in-one-day