I'd imagine there is quite a lot of legal pressure against doing that. Not knowing who your customers are seems like the sort of thing that would eventually involve lawyers.

mullvad.net was interesting to me because I could pay with Monero, meaning that they may actually have no data about me whatsoever except whatever is technically required for a VPN connection. Pretty cool company but it seems like the sort of model that would struggle in most countries with the amount of financial monitoring that tends to be in place.