The idea behind is a decent society doesn’t let people fend for themselves. They will always be looked after. But if people want to make more than a guaranteed basic income, they should have that choice. It operates in the opposite manner to welfare programs that forbid a beneficiary from making more than they receive in benefits. Welfare creates a perverse incentive not to work because there is no safety net in place if you do; UBI in contrast, lets you keep your income and earning more is not at problem if you want.
Those who will not work should starve. Simple.
OK, I’ll assume you’re doing/will do that forever with your children, giving them a minimum base, and they can earn over that.
If not, why should I do that for a stranger?