What will delay UBI adoption is that governments can't afford the current welfare systems, many of which are unsustainable, let alone a much bigger one. France can't even raise the retirement age by like one year due to massive protests but they have to, as the current retirement age is unaffordable.
We have more wealth in the world than ever before. The problem is that it's distributed through something like a power law curve where a tiny proportion keeps all the wealth. If we changed that wealth distribution to something closer to linear then we'd have plenty of wealth to fund welfare systems while the rich can continue with their lives of luxury.
