Its just larger block size so its slightly more scalable and at times in its history was more profitable for bitcoin miners to switch. When you look at bitcoin you need to think in terms of either a few transactions per second or thousands (if you really want to try to scale it as a currency, although volatility still wont work...) Bitcoin cash is nothing but a small bandaid that wouldn't help scalability for more than a year or two.. since doubling something very small is still a very small number.. I personally am okay with the higher fees and transaction times of bitcoin in turn for it being more decentralized.. but bitcoin cash is an example of not being okay at anything.. and not at excelling at decentralization like bitcoin.