The problem with UBI is that not only does it give people an incentive to not work (as 25% of people in the study stopped working, even when they presume that the money would stop coming at some point) but, at a national level, it also requires a massive tax hike on the people who do work, which disincentivises work.

It would have an inflationary effect on basic goods and services. If you're renting and everybody is getting an extra few thousand a month then landlords know that they can charge a bit more since everyone has that money. Same with staple foods.

The cost savings don't make sense. An argument is that it will actually save money because the government will be able to abolish disability support and welfare, get rid of free healthcare, etc. But this ignores the fact that a lot of that stuff has unequal demand. You crash your car, your leg gets cut off, go to the hospital, they spend $100k on making sure you survive (specialised machines, a team of doctors and nurses, medicines, recovery and physiotherapy). How's that work under UBI if the government isn't paying for it anymore, who is? Or say you have a child with a disability, it's still going to cost more than the UBI.

Also, regardless of the economic system - could be feudalism, communism, the bronze age palace economy - redistributing income away from producers towards people who don't work (or even work less) is going to have negative effects. There is lot more demand for garbagemen than there are people who really love being garbagemen and wouldn't mind the high taxes. Take a look at the UK: the percentage of the population that are pensioners keeps on rising and the government keeps giving them more money - it's gone from 2% in the 50s to more like 10% now - all money that could be spent on other things that could grow the economy.