In my experience bitcoin cash is a fork of bitcoin even BCH is faster and cheaper to use due to larger blocks but still it'a seen that most of the people are using BTC than BCH so why is bitcoin doing better than bitcoin cash?
Everyone will use this coin in everyday life. Bitcoin will be traded on the exchange as gold. I think this is the most correct distribution of roles.
There is no need to compare Bitcoin with gold, because Gold is a physical body and has a much higher value. Although it can be said differently, they are residents of completely different worlds.
Today, both Bitcoin and Bitcoin cash may be more promising investments. But if we consider future prospects, then ethereum has much more potential.