E2EE and onion routing protocols use similar cryptography to "mix" and "obscure" inputs and outputs. It is very much the same approach, just that we don't call it "message laundering" because we as society have come to appreciate private communication.
I would tell you to just look at the Tornado Cash code yourself to verify this, but alas...
E2EE generally doesn't obscure who is talking to who AFAICT.
Onion routing does, sure.
Ethically I find that area very much a double-edged sword. It's great for privacy and people evading speech-hostile regimes, but it does also enable trading and propagation of CSAM etc. It's why I've never run a Tor or Freenet (does that still exist?) node, I don't want to support that stuff with my resources.
E2EE obscures everything, that is why it is called end-to-end. If Alice and Bob and John and Piper are all communicating with pseudonymous names in a Matrix room, you do not know who is talking to who or what they are talking about.
> E2EE obscures everything, that is why it is called end-to-end
No, it just encrypts between the ends, hence it being called "End to End Encryption". You're going beyond that if you're talking about hiding the fact that the origin and destination are talking to each other at all.
> If Alice and Bob and John and Piper are all communicating with pseudonymous names in a Matrix room, you do not know who is talking to who or what they are talking about.
Maybe so, but in other E2EE products the fact of communication is not obscured to someone who has access to the traffic. E2EE just means there isn't a server in the middle that decrypts everything before relaying, or any sort of master key they could use to do that with.
Matrix looks like a great system, but it's not the only E2EE product, nor does it define the term.
I would tell you to just look at the Tornado Cash code yourself to verify this, but alas...