Water does, though. So in this case gravity would be the water and boiling water would be a black hole. One could argue boiling water adds entropy to a system

Water does, though. So in this case gravity would be the water and boiling water would be a black hole. One could argue boiling water adds entropy to a system (if its power source comes from outside the system) and that it's worth studying the effects of this added entropy in detail. Like how far do I need to be from the water to maintain homeostasis? Does the heated air around the water create small currents which cause a thunderstorm in Kansas? Testing these kinds of questions is essential to the scientific progress we've made which even allows us to definitively say what water is and isn't.