Which p2p protocol is battle tested ?
Torrent is not web ready.
Webtorrent is not battle tested.
Ipfs does not work at scale.
Discussion
Torrent protocol is battle tested. And who said it had to be web ready ? Why should this be a constraint ?
That's all about use case.
Torrent: open your favorite torrent app on your desktop, you download and seed some content.
Nostr. You open your favorite webapp or mobile client, you publish some meme and finally close the app.
The Nostr client would embed the torrent client.
This is a common practice with the protocol in some apps. e.g: Steam uses bittorrent for application/update downloads.
Up to the client to handle the seeding and the rules to apply ( service workers to keep seeding in the background for X time even if user is not on the app actively ).
The idea is that this way the files content wouldn't be in the nostr protocol and it wouldn't require additional protocol design. It'd be up to the client to handle the content retrieval, sharing, caching, etc.
Obviously there should be a way for user to fine-tune the behavior of the client regarding the torrent client, but i see this as another matter