Minimum wage is barely (in many cases not even barely) enough to live on. Raising minimum wage is a herculean task that rarely succeeds. Federal minimum wage hasn't been raised in 16 years. But we'll have not only a livable UBI in 20 years, but one that's enough to "retire to a life of leisure"?
Minimum wage isn't directly comparable, because that's the government setting a rule on what two private parties can agree to. It's not the government but the employer who pays it.
UBI is distributed by the government directly, so it's basically a question of what gets taxed, how much inflation results, and whether that inflation and taxation proves more unpopular than the UBI is popular.
This is silly. To a first approximation, zero percent of the opposition to minimum wage increases comes from a principled stance of "I support taxation, even high taxation, but I am opposed to the government interfering in private labor market contracts"; 100% of it is from "they're taking my money!". There is no reason to expect any less opposition from the much, much larger amount of wealth redistribution which would be required by UBI.
What does minimum wage have to do with taxation? It's not the government paying those wages, it's McDonald's, and the opposition to it comes from people who say it will result in McDonalds closing stores or replacing cashiers with touchscreens rather than paying more for employees; ie, low-value labor simply becoming unemployable rather than getting a pay boost.
There are a lot of counterarguments to a high minimum wage, some even from UBI proponents, but none of them are "they're taking my money" because that doesn't make sense in the context of a minimum wage.
You can frame the opposition to a minimum wage that way, e.g. if you raise the minimum wage then the cost of a Big Mac goes up and you're the one paying it. Or, suppose you're a small business owner who employs three people and you pay them each $20,000, and then after paying them you're left with $50,000/year for your own salary. If you were required to pay them each $30,000 then you'd be left with $20,000 yourself, and that might make you pretty unhappy. More to the point, it might make you close the business and go get a job doing something else, and then those three people lose their jobs instead of getting a raise, which is precisely the argument against a minimum wage.
But that still doesn't apply to a UBI, because a UBI is universal. The person buying the Big Mac or running the small business gets it too, and the breakeven point would be around the average income, so you don't have the problem the minimum wage has where the people paying the cost are often the people who weren't making that much money to begin with.
There's plenty of reasons to doubt, but you could reframe it as "lower pension age to zero".
In optimistic scenarios, if AI can do so much that nobody's even getting paid to make robots, then AI are making robots that also makes the cost of living lower.
In practice, I think that the path from here to there is unstable.
We can't even get universal health care or a decent minimum wage through the opposition from our oligarchs, and those are much, much smaller asks than UBI. Why on earth would you expect UBI to be possible, never mind inevitable?
"Universal healthcare" is typically used as a euphemism for government-operated healthcare providers, which would wipe out both the health insurance industry and a lot of private healthcare providers. You get the strongest opposition to a policy when a specific group sees it as an existential threat, because that group will then organize to lobby vigorously against it.
Minimum wage is a price control. Price controls are trash economics and should not be used. They're a political issue in the US because a federal minimum wage is doubly counterproductive, since different states have a different cost of living. But because of that the states with a higher cost of living see a smaller deleterious effect from a higher minimum wage. Then representatives from those states can claim to want to raise the minimum wage so they can paint their opponents from the lower cost of living states as the villains when they fight against it. But nobody really wants to increase it because it's a bad policy, most of the proponents are from states whose constituents wouldn't even be affected because their state already has a minimum wage in excess of the federal one, the proponents just want to make their opponents vote it down again so they can cast aspersions over it.
A UBI is equivalent to a large universal tax credit. A slight majority of the population would receive more than they pay on net because the median income is slightly below the mean income, which creates a large base of support. If everyone voted purely in their own personal financial interest it would have simple majority support. Meanwhile most of the people who would end up paying on net would only be paying slightly (because they make slightly more than the average income), and in general the net payers are a very large diffuse group with no common interests or organizational ties to one another.
A UBI is a thereby easier to bring about than either of those other things.
Your argument pays no attention to how economic behavior changes due to existence of UBI, ie, how many people choose to work less and thus drop out of the pool of people paying in.
It doesn’t really make sense to me to live in a world where people are given money by the government while simultaneously expected to pay taxes. Its a high overhead when the same could be achieved by printing money and handing it out to everyone equally (which acts as a redistribution of wealth same as taxing the rich and paying credits to the poor, since it devalues the dollar as more supply is added)
