This is just an initial proposal, and probably will reduce down to one with developer feedback and implementation experience, which is normal for API development.
Whether it's one shape or the other doesn't take affect the network protocol underneath.
If you have constructive ideas of how to simplify the protocol underneath or the API, you can share them with the authors. The people that work on that APIs are always looking for constructive feedback
WebRTC (with p2p) was done within the W3C, as was a p2p QuicTransport. And this new API is similar to the open screen APIs that have been done in the W3C.
So I'm pretty sure work like this can be done in the W3C.
I was one of the original authors of the p2p QuicTansport API and the WebTransport API which is based on it.
I've also recently discussed this new local p2p API with the authors. And I'm in the favor of it, at least in principle.
The difference is that local p2p does not require signaling like, say the p2p done by ICE, WebRTC, or p2p QuicTransport. So for some uses cases, this would be better. And, if done right, this would fit well into a cohesive set of APIs that cover both kinds of p2p.
I'm also in favor of making APIs low level, but I'm not sure if raw sockets is going to work. Keeping congestion control working is pretty important.