They don't have to lose users to lose value -- at least for a while. But their hydra heads are spread everywhere. Every single "Like" button on a 3rd party website is a tracking pod and this has been well documented. Every single advert hosted by Facebook is a tracking pod as well.

Your engagement might be low -- mine is almost zero -- but you are still a source of data even if a reduced one. I am not sure even disabling Javascript altogether will help; I am pretty sure they fall back to techniques like your IP history, known devices from which you logged in and few other such techniques.

My gut feeling is they are holding on very tight to their personally identifiable information harvesting practice and won't let go of it anytime soon. Hope I am wrong.