...Personally, I am using Binance. ...
Binance is a really good exchange for trading and it is the main one for many. But one exchange, even a good one, will not be enough to buy new coins for long-term investments that are not represented on the Binance. It is on such exchanges as Hotbit and MXC that such new coins appear first of all, which have a relatively low price.
We need have many exchange account kinds because when any new coins not listed on Binance we can get profit from other exchange, but last morning I arbitrage BTT coin from Binance to my local exchange, this proof we need many exchange market because profit not only coming from trading but some time we can earn from checking different price coin one exchange with other exchange and good for arbitrage.