Good thing most of us don’t live like animals or think like you: we live in a society.

Even in the US, at least some effort is made to not let the disabled who can’t care for themselves or financially support themselves die in the street. https://legalclarity.org/what-does-ward-of-the-state-mean-for-adults/

The appointment of a state or public guardian is a measure of last resort, as courts prefer to appoint a family member whenever possible. State wardship occurs when the incapacitated adult has no spouse, willing family members, or a previously designated agent to take on the responsibility.