You know what the biggest human trafficking and enslavement cartel is? Prison and the criminal “justice” system. The loophole of the 13th Amendment in the USA allows people to be forced into labor against their will if they are convicted of a crime. The law doesn’t care what crime. The victims of it are almost never those precious middle-class white families in the suburbs. They are the black families who are arrested for misdemeanors like jaywalking and sentenced harshly, who are arrested and sentenced to decades in prison for something as basic as selling pot.
The other main victims of human trafficking are sex workers forced into the oldest profession because they have few other sources of income available, who are just as often victims of police violence as violence from their clients. Again, the victims are not your precious middle-class white families in the suburbs. The victims are generally black women struggling to make ends meet because their husbands got arrested and imprisoned for decades for misdemeanors (usually with a ‘resisting arrest’ thing thrown in just to make it stick). If they’re white, they’re usually trans and usually forced into that situation by the white middle-class suburb crew throwing them out for the crime of existing, usually religious (I knew pleeeeenty of Mormons like that), and usually just as bootstraps as you.
But considering your biggest concern with a UBI is that people will turn to crime out of boredom, I don’t think that you’re concerned about it. Idle hands do not make the devil’s work. Distrust and envy does.