Taking a long-term view, UBI is a good idea, full stop.

Societies' advancements in technology & productivity decrease the effective cost (as percentage of GDP) of meeting the very base needs of a human being. Food, cheap medicines like tylenol & antibiotics, most facets of human life are dirt cheap from a production perspective, and this trend will continue from automation.

This means someone who is currently unproductive can be subsidized to survive for 10 full years, and if there's even a small chance they become a high-productivity individual afterwards then society comes out ahead on net value. The actual numbers depend on how low we can push production costs with automation, but in the limit as human survival cost approaches zero relative to the economy, the only rational decision is to subsidize all human survival and work within that framework to encourage citizens to be even more productive. After all, if someone dies of lack of healthcare, or starves, or lives in the streets and doesn't know how to get back off the streets, that's a net loss to humanity in opportunity cost. If that person had just been subsidized through their hard times, there's a non-zero chance they become high value to society.

UBI allows us to reap these benefits in an efficient manner: using the free market. But, speaking today not in the long term, there are exceptions to the low cost of human survival which would hamper UBI from being effective.

In our (American) society, there are a few base needs that we haven't adequately driven down costs. Shelter mostly, also any healthcare that is more involved than taking a pill a day (notably: seeing a doctor). Humankind in general CAN make these costs low for the most part, but American society in particular has NOT made these costs low.

We need to address the housing & urban development crisis, and we need to address the healthcare crisis.

The housing & urban development crisis is a system of regulations and inaction that have simultaneously limited the amount of housing near desirable locations, while failing to provide efficient transportation to bring people in from less desirable locations. In other words, housing costs are dominated not by the cost to build a house, but the cost of land. This can be addressed by reforming our awful & piecemeal zoning, construction, and transportation systems and their respective regulations. Optionally, some might suggest that we try to fight against the ongoing trends of urban consolidation; if people have a reason to move to upstate new york or the midwest, instead of to NYC, then housing costs aren't a problem. But right now all economic incentives point to moving to NYC metro, given the choices, and personally I don't like to wage war against the tide of the free market.

The healthcare crisis is one of rent seeking by insurance companies upon our awful half-assed nearly-free-market approach to healthcare. Quite simply, people don't have choices (your healthcare options are restricted by your insurance, which is restricted by your employer), and no prices on anything are known ahead of time. This adds up to an ultra-inefficient system. By doing just about anything that stops the rent seeking of the insurance system upon the healthcare system so we can more efficiently treat a healthy society (there are free market solutions, but personally I would put my weight behind medicare-for-all).

In conclusion, if we give everyone $1000/mo, that's going to get funneled into bidding up rent in big cities or surprise healthcare bills. We need to solve these issues with our free market before we take a free market approach to the common welfare; until then I would advocate more targeted approaches that are less likely to invite rent seeking behavior (foodstamps and such).