Used it dozens of times, usually works fine for the popular content.

Good quality, barely any buffering.

The niche content may be too difficult for a "live" streaming experience.

I have; it worked flawlessly for content that was decently seeded. And that's without the sorts of table stakes you'd expect for a streaming platform like the same content encoded at different bit rates, but chunked on the same boundaries so you can dynamically change bitrate as your buffer depletes.

And I'm not sure most people actually care if their home hardware is being used for whatever by the service they're using, or else there'd be pushback on electron apps from more than just HN.

The sense I always got from Netflix's P2P work was that it was heavily tied into the political battles wrt the BS arguments that Netflix should pay for peering with tier 2 ISPs. Did this work there continue much after that problem went quieter?