SR isn't run on I2P because I2P sucks 1. If an I2P site has *any* down time it is deanonymized. Every node routes for other nodes. Getting a list of all nodes is as simple as adding a few nodes to the network. If you keep monitoring a hidden sites up time you can correlate its down time to the down time of an I2P router and identify it. 2. I2P is used by a few thousand people (almost all of whom participate as routers) and has a few thousand routers. You can get a list of all I2P routers by adding a few nodes to the network. Now when you find your vendors rough geolocation when they mail to you, you can assume they are the one I2P IP address that is in the same half of the country that the vendor shipped from. SR is run on Tor because even though it sucks, it sucks less than the alternative options.