Humans are not a hive mind, we are individually embodied beings with unique perspectives, experiences, and priorities. As such, humanity is only better off if every individual is better off, not if some imaginary aggregate is. Likewise, individual well-being is not relative to the aggregate past but relative to those around us in our current circumstances. The more obvious inequality there is, the more less happy individuals there are, and that means that society as a whole is worse off.
Your liver damage would not consider you to be better off if you got a nice haircut, and neither should your brain. It's really irrelevant how well some part of you is doing if some other part is suffering an existential crisis for which the entire corpus suffers ill effects.