I think the point is: imagine government banned bars, because some percentage of rapes involve perpetrators stalking victims in bars and getting them drunk.

Perhaps more directly - if we're trying to stop sex trafficking by shutting down the places where victims meet clients, we're going to have to ban streets.

Or why can't we ban churches because pastors can use them to rape or molest church members?

Most monetary transactions involving victims of sex slaves involve money, should we remove it too?

He's saying that this affects far more legitimate users than sex traffickers by multiple orders of magnitude, while at the same time not preventing sex trafficking from taking place anyway.

No, no, we don't ban money, we just move to systems where the government gets to monitor all your financial transactions in real time and they get to selectively block those they don't find morally wholesome.