Low latency will help you to get your order executed at spot price and without low latency there will be significant slippage and again the account book will also be re-quoting without low latency and it is because of high scalability and low latency. The exchanges are still centralized and when it is about scalability, centralized exchanges have still the upper hand and they continue to dominate the exchange market..
But I think trading a decentralized cryptocurrency in a centralized exchange does not make any sense and in the next 2/3 years more blockchain projects will evolve to solve this issue and the decentralized exchange can also be able to deliver that kind of low latency in future.