The dynamics aren't the same, the UBI case has a much weaker negative feedback loop than minimum wage. The percentage of the population that benefits from ratch

The dynamics aren't the same, the UBI case has a much weaker negative feedback loop than minimum wage. The percentage of the population that benefits from ratcheting minimum wage is much smaller -- they are intrinsically a permanent minority. Ratcheting UBI, on the other hand benefits a much larger population whose growth as a percentage of the population is effectively unbounded by negative feedback. It would be very easy to arrive at a pathological equilibrium where the majority of the population has a strong incentive to vote for short-sighted expansion of UBI at the expense of the minority. Once in that mode, addressing the pathological consequences of that politically would be very difficult unless mitigations were designed in from the beginning. It is possible to design negative feedback loops for the UBI case to greatly mitigate this issue, but it tends to be avoided by UBI proponents because most solutions have varying degrees of unpalatability.