the tor onion network. But no exits to clearnet.
Everybody contributes bandwith. And because everybody contributes bandwith, privacy is created because you can never know if you reached the end of the chain and found the creator of the first network request.
In theory it’s a lot more secure than the tor network. In practice it gets 1/100th of the funding, because you have to be a computer nerd to even install it, need a computer to keep it running 24/7 (longer you run, more privacy) , while tor browser “Just works” and can start providing privacy to everybody right away.
If this was the first time the world heard of onion routing, then yes.
Now they can realize that you’re probably just one step in the chain. And with i2p there’s no way to know if they even reached the end of the chain (provided you host i2p for long enough).