Binance is asking KYC because they under the supervision of state SEC which made the centralized exchange platform. And good performance make one to be the number one in any race of competition so for Cz to take that position means he has credibly done well in the crypto market.

I don't think there will be any harm in bitcoin if Binance left the exchange market. There will be a replacement of it. Bitcoin does not depends or rely on Binance to survive instead it is Binance that depends on bitcoin. So for Binance leaving the crypto scene will not have any effect.

USA is not a big threat to the crypto market but they are trying to regulate and control it but I don't think that can also work out. They can only control the centralized exchanges and centralized altcoins. But finally USA will also support cryptocurrency in the world. And at that time bitcoin will skyrocket to the cloud.