Yes you are right. Exchanges occur frequently, but sometimes it turns out very profitable to make money on it. For example, at first, the exchange always lures to itself all sorts of bonuses. The minimum amount to withdraw. And sometimes you can even buy coins on one exchange and sell them on another. Not all exchanges allow this, but sometimes new exchanges have such an opportunity. As for this company, I have not tried it yet, but it looks interesting. Bonuses I love.
The more exchanges there are, the more chances to earn on inter-arbitrage. It has always brought and will bring good profits!
Earnings on inter-arbitrage between the exchanges is very difficult. To do this, you need to have special programs, and spend on this time and effort.