Bitcoin gained it's value when people started trading it and even when we didn't had any actual trading platform people were doing it and then the exchange came and the growth went to next level
And it's not the exchanges that created the mandatory KYC requirements but the government when they realized that it's not a bubble and it's not going to pop as we expected so we need to find a way to control and censor it so they went after every centralized platforms. If we have no exchange the operation of bitcoin in terms of utility will almost stall because most people use bitcoin as investment not really as payment method but it will survive and will find the way.
Exactly I agree Bitcoin value first grew naturally means people traded it with each other. Creation of Mt. Gox boosted this growth making it easier for people worldwide to buy and sell Bitcoin. Governments ignored Bitcoin first thinking it was temporary trend but as it became more valuable they started to worry about its use for illegal activities. This led them to force centralized exchanges to require user KYC with this they trying to control technology designed to be free from control. But most people see Bitcoin as investment other than as pay for things and exchanges are big part of that. Bitcoin open ability to send money directly between people would still work even without them. Entire story of Bitcoin is continuous struggle between its original idea of decentralization and rules of traditional financial system.