Traders leave Poloniex for different reasons: custody, KYC requirements, fees, or market coverage.
What custody actually changes
Poloniex's fees are 0.01% for makers and 0.04% for takers.
The maximum leverage on Poloniex is 75x.
Poloniex is not available to US residents.
Poloniex charges 0.04% taker; Canborsa charges a flat 0.07% per side (0.14% round trip).