I'm almost certain that provably fair is a term used in online gambling and not with exchanges and trading platforms. 
Cobinhood is the only exchange with no trading fees, but not that recommended as there aren't many coins supported. I would suggest using Binance with BNB to get better fees.
I agree with you that Binance is the best exchange fir trading. There we can trade with so many coins and we can use their BNB coin for lowest trading fees.Cobinhood is the only exchange with no trading fees, but not that recommended as there aren't many coins supported. I would suggest using Binance with BNB to get better fees.