Hello, I'm not that informed about UBI, but here is my arguement:
Everyone gets some sort of income, but wouldn't companies just subside the income by raising their prices? Also, do you believe capatilism can co-exist with UBI?
One method of structuring it is that if UBI is $20k/year, then you have $20k/year taken out as taxes as long as you have a job. The income is neutral, so there's no basis for companies to raise prices.