Basic income is meant only to give people the very basics they need to survive. Food water shelter and maybe some clothes every once in a while.

Survivng is what you give back to society for your "free money". There would be less bums shitting in the street, stealing for food, or squatting in houses. All of which costs money to fix/prevent. We already have programs like this for poor people, but the amount of money that goes into running these seperate programs and checking to see if people fit the criteria is a ridiculus ammount.

There is also the argument used by most followers of basic income that it is specifically meant for when automation has gotten to the point where we really don't need most humans to do work. There is little point in having 8 billion programmers and engineeers. Basic income allows for people to survive in an age where there is more then enough production to go around. This allows them to spend their time doing things that may not make a survivable amount of money, but still holds value to the world. For example, art.