Again, I don’t think that’s true. Junglefowl live in incredibly dense tropical locales that would make it very difficult to hunt them.

As well, I think the concept that we would kill all chickens off so they would therefore be extinct because we have no use for them is, well, counter to what this entire post is about and not really much of a thought experiment. You could say the same about dogs, or cats, or any other animal humans decide to decimate. Hell, even each other at times… Even with junglefowl we could burn down their habitat until there were none left.