Eth was created as a result of the DAO "hack".
In the btc case, it's a dispute between the developers and the miners.
ETH forked over a disagreement on how to handle DAO. BTC is forking over a disagreement on how to scale. OP is absolutely right in that Bitcoin Cash could overtake Bitcoin Classic/Core in the way that forked ETH overtook ETH classic.
Litecoin could also dominate. But for some reason it's not. Hmmm. I wonder. Maybe it's because bitcoin is better?
I use both ltc and btc. ltc has been faster and cheaper to transfer in my uses. IMO ltc is the best token of value over gold,fiat,btc,etc. because it has the more efficient tx qualities and all of the collateral benefits of btc. Why is btc better in your view?