With universal income, people are paid to breed.
Professional breeders are undesirables.
Professional breeders represent ballots.
They will have a strong sense of entitlement and will not be satisfied with the minimum income. They will live a life of crime.
IOW exactly what is already happening-
the govt promoting the highest birth rates among those least able to parent while penalizing couples and promoting single moms having more kids.
You have seen this in the urban centers and it’s happening in depressed rural regions of flyover country- illegitimacy, drug use (e.g, fentanyl).