I find it unlikely that genuine UBI will be implemented in any country in the near future, although, to be fair, history of mankind has brought surprising changes in the past such as e.g. the complete downfall of Feudalism.
I just wanted to make clear that it's possible to implement UBI. There are many reasons against UBI, but not the ones you gave.
Personally, I'm against UBI for two reasons. First, it does not solve the fundamental problem, which is capital accumulation an ever increasing gap between the rich and the poor. The more money you have, the more money flows to you, and the gap has grown insane. Unless this trend is addressed and reversed, even UBI cannot prevent massive social unrest in the long run. Second, UBI makes it mentally and morally easier for employers to fire people and to lower wages even further. In the end, it will lead to a grossly impoverished class of UBI recipients who will work 6 days a week for $3.25 an hour to supplement their meagre UBI.
In my opinion a classical welfare state, maybe with a negative income tax, strong worker protections, tax-funded education and health care, and strong means to prevent wealth accumulation are the only ways to tackle the problem in the long run. Reforming hereditary laws and stopping almost all "financial products" would be a good start. Right now, once you have reached a certain threshold you can just live off by speculating on Wall Street and juggling around virtual money without ever producing anything of (non-monetary) value. That shouldn't be possible at all.
A deeper problem is that the whole model of existing economy is flawed, because it's based on permanent expansion, which leads to fast exhaustion of natural resources. It is simply not maintainable on Earth for more than 200 years from now.