Standalone network layer privacy for cryptocurrency is useless. No matter how good your network privacy is, cryptocurrencies are like Twitter for your bank account... every transaction leaks an amount, source and destination to everyone. Hiding your IP doesn't fix this.
For any real privacy, you must hide the transaction graph (from, to, amount). Do that and your payment is an opaque blob + an IP address. All the world learns is that your IP made a payment, but not to who or for how much. No big deal. So no network privacy, no problem? Not quite
The party who receives your payment does learn your IP, and, unlike everyone else, they know who it's to (it pays them after all). E.g., Pornhub learns your IP when you pay them. That's awkward. So, do you need a network privacy layer? Yes, but not a cryptocurrency only one.
Network privacy for a cryptocurrency doesn't work. It hides your IP when submitting a payment to Pornhub. But it doesn't hide your IP when browsing Pornhub's website, clicking signup, or streaming video. To hide your IP there, you need a general solution. Tor or the like.
