If they were my adult child, I would probably purchase a home for them to live in so they don't end up homeless. I know two people who have done this for their adult children. One bought a house with 4 bedrooms. Their son lives there and they rent out the 3 other rooms to people who are in a similar situation. The other bought a small condo with one bedroom because their son really can't live peacefully with other people.

I would also try to get a diagnosis that would enable the adult child to apply for SSI.

I’d actually suggest increasing structure and responsibly. Try volunteering 10 hours a week and increase hours slowly. Develop a schedule. Cut the screen time and try to make sure he goes to counseling. Ask his doc for a psych screening.

Do you think there is a mental health component?

Is this the same 20 year old whose dad said they were acting like a moron?

Kick him out of the house, for his own good.
Tell him it’s time to grow up and be an adult

How old? What level of education? Is there mental illness involved? Are you funding their lifestyle? Have you given them use of your car? It’s hard to say how I’d react without more facts.

He can create a job for himself and be his own boss.

Do they have a diagnosis? Not anywhere to this extreme but my bipolar sibling had tendencies like this before being diagnosed/treated

I certainly wouldn't let them live with me. I'd tell them to let me know which bridge they will be living under.

Surely this isn’t brand new? Sounds like ODD or something?

I'd cut them off. They can figure out how to find meaning in not being homeless by earning money to pay rent.

Seek therapy and cut them off

Cut off

Seek therapy.

What do you do with an adult child who can’t keep a job and has issues with the concept of working? The longest job they kept was 2 weeks and they usually quit saying things are pointless, they dislike the job and have a problem with authority. They seem to be fine with the prospect of being homeless.