The number of employees of the exchange depends on the size of the exchange and on the number of traders on the exchange. The more popular the exchange is, the more employees it needs.
Now cryptocurrencies are extremely popular and provide great opportunities for making money on trading. Therefore, cryptocurrency exchanges are very popular and they have good trading volumes and a lot of traders.
Now traders are carefully paying attention to the set of tools that the exchange offers. Therefore, they carefully choose an exchange for trading, taking into account its security and a set of tools.