In antiquity, the Roman Empire practiced a flavor of UBI, in that the city of Rome provided free wheat (later, bread) to its poorer citizens. This was no trivial matter, as importing and distributing (to 200k citizens, at its zenith) were complicated and expensive. This was a stable arrangement for centuries. After the loss of North Africa, the wheat stopped flowing so regularly, and it grew increasingly expensive to support this benefit, but giving it up was politically impossible. Rome collapsed, and the experiment ended.
Across the world, Lao Tzu said the wise lead by emptying hearts and filling bellies. There’s also some famous saying “Civilization is always four square meals away from collapse”.
What can we learn from this? UBI makes sense when times are good, when there is surplus and trade. But it’s very hard to revoke what a people are used to receiving for free. It might be more efficient to teach a human to fish, than to feed him fish “for free” every day.