UBI is implemented tomorrow. Every citizen gets $1000 per month.
Landlord now knows you have an extra $1000 that you never had before. Why wouldn’t the landlord raise prices?
Now you have an extra $1000 a month and instead of eating rice and beans for a few meals you go out to a restaurant. The restaurant owners know everyone is eating out more so why not raise prices and maximize shareholder profit as always. The restaurant/corporation is on TV saying, “well, demand increased and it is a simple Economic principle that prices had to increase. There’s nothing we can do about it”.
Your state/country has toll roads. The state needs money for its deficit. UBI is implemented and the state/country sees it as the perfect time to incrementally raise toll prices.
Next thing you know UBI is effectively gone because everything costs more and billionaires keep hitting higher and higher all time net worth records.
I think everyone already had a taste of UBI from the covid stimulus checks that raised the costs of everything.
The correct answer is to guarantee food, medicine, shelter, and education. This provides a bottomline for all other sellers and keeps prices down as well.
That’s not what happened. During Covid, stuff got scarce, because supply chains got interrupted (e.g. by lockdowns in China). People still wanted/needed that stuff though and the ones that could afford it paid more money for it. the companies just “forgot” to lower the prices again after covid, since everyone got kind of used to the higher prices.