I don't know why someone would look for virtual crypto cards (is that what we're talking about here?) that would be linked to a crypto wallet? Virtual cards (Visa/Mastercard) that can be bought for cryptocurrencies and paid with online or added to a mobile wallet and paid with at POS devices are much more logical to me.

Even such cards have limitations, and if they cannot be activated with VPN/Tor, it is difficult to be anonymous with them, especially if you pay through a POS device. Be that as it may, if you're trying to spend cryptocurrencies that are in any way connected to something illegal, sooner or later someone will knock on your door, especially if it's a significant amounts.