>It's a way to make sense out of the world and to have some shred of a sense of agency in a world where a person otherwise has no power.

Wouldn't poo-cassos be better framed in an institution cell away from the other 90% of society? That way they can get the mental support they need and rebuild their agency. If you don't have agency, you need conservators to help you address it. For children, those are parents. For adults, that's the state.

Otherwise we're admitting participation in a society is pure benefit without any responsibilities.

Because you're a decent person. Or, put another way, if you choose to disregard the social contract, you show your lack of quality of character. Either way, it's still a choice and not forced upon people by their circumstances.

No, it's mostly severe drug addiction and mental illness.