I think not so much people use bitcoin cash, but maybe if there not happen the fork maybe bitcoin cash value more, but i think is possible to survive if people will use it, but i don't know if the price will grow too much.
You can see how many people do by using this site
https://txhighway.com/BCH has a very wide highway but there are almost no transactions going through. Bitcoin has a much smaller one but enough transactions to keep it occupied and not enough to cause a jam. If Roger doesn't think of something new pretty soon his coin will not look attractive anymore to those who want to differentiate.
Since nobody is using BCH its value must come from differentiation pretty much like the value of most other altcoins.