You may as well say, "KYC might deter a large fraction - let's say about 99% of these malefactors"
There's no evidence provided for these numbers. It's one thing to make an assumption which is counter to your argument - "Even if 99% of criminals are deterred, it creates an unconscionable burden upon those whose identities are stolen" or etc.
It's quite another just to assume your own argument. Let's assume cops prevent 99% of crime - it's worth their brutality or whatever. Let's assume cops prevent 1% of crime - we would be better off with 1% more crime and no cops or whatever.
It's absolutely pointless.
The article goes on to immediately compare KYC with widespread facial recognition. Why are these equivalent?
They could at least try to engage with arguments for KYC - that large financial institutions should not be making life easier for criminals. Historically, a bank obviously knew their customers - they had to open the accounts in person, talk with the bank manager, etc.