After all, if you believe their rhetoric, giving someone $500/mo should be the same as giving them free bread, eggs, milk, some clothes and some movie tickets.
I wonder why... Maybe, the reality is that over time our 'Basic' needs increase. In certain parts of the world shoes are still considered a luxury whereas in others, Nikes and Adidas are considered 'basic'. 50 years ago car ownership was a luxury even in most 'developed' nations, as were televisions. Now they're considered 'Basic'.
The reality is, the people touting UBI as a way forward suffer from having a thoroughly static and isolated view of the world. They fail to see that value creation is what's important, and drives society to further itself. As value creation goes up, the definition of 'basic' increases with it. I'm not for a minute advocating that the current system is anywhere near perfect - the wealthiest in our population are questionable value creators while at the same time there are value creators scraping by in the world so the way we reward people needs a rethink.
I don't profess to know how to solve the poverty crisis and I very much want it to be solved as a citizen of the world. What I do know is that the only way to do it will involve reforming education so that future generations are inspired to advance humankind and create value in the process.