The only reason Bitcoin Cash works thus far is because nobody uses it. If it were to be working at scale (that is, full blocks) people running nodes would get kicked out of the network, eventually leading only to datacenters running the BCH network.
The point is that Bitcoin Cash network is already centralized but the market doesn't care. The current transaction capacity is at 8MB which is equivalent to 2.5 million transactions per day. As long as the tx volume is below 2 million per day, or 6x the current rate of bitcoin, the fees will very low.