So creating a cryptocurrency exchange platform that is registered company is completely legal, even if KYC and SOF (Source of funds) are never required, providing maximum anonymity to its' users?
That's how it should be and these are some basic principles of Bitcoin and cryptocurrencies.
It is something else entirely that the narrative of mandatory KYC was created due to the fight against illegal business and crime, although this is most often applied to have a better insight into all money flows, most often legal ones. If money flows were free and in privacy, on what basis would governments charge taxes?
Also, the area is quite undefined, and even though no-kyc exchangers are legal, they can be interpreted as illegal somewhere.