For now I used Bitforex and Probit exchange, because through this platform I got earned weekly on these two. In short, earning cryptocurrency is not depend on how big the exchange site platform is. It is always depend in the hands of the individual traders of how He/She going to do it. And this is what I did now actually for a couple of years now.
The first and most important thing aside from trading is the security of one's assets and this is what OP is looking for. I am not comfortable with the exchanges you have suggested. Bitforex know to selectively scam, lock up people's accounts out of nowhere and list scam IEOs and tokens. The other (probit) is very unpopular. Honestly, it's my first time knowing about.
Why would you suggest shady exchanges