I mean that the people who brought the person to life are responsible to make choice that will ensure theirs long term survival.
e.g my grandmother had a brother who their brain stopped developing at a very young age (afaik 5), the parents ensured and my grandmother ensured that my uncle lived a full (but sadly difficult) life living and been taken care of by them and then my grandma after they passed.
So what does that actually mean in reality?
Have you ever asked them what it was like to financially support him like that? Do you actually want the world to work that way?