...Although having several exchange account is good to diversify your trading activity and minimize risk in case exchange bankruptcy.
As a rule, tokens are not listed on all exchanges, and this is the reason that I have several accounts on different exchanges. In addition, due to the difference in the price of a coin on different exchanges, you can engage in arbitrage trading and this provides an additional opportunity to make a profit by buying a coin on one exchange and selling it on another at a higher price.