UBI is a solution that won't work, for a problem that doesn't exist.
This story that "all the jobs are going away" is false. Just take a quick look at the Employment Rate (not the Unemployment Rate) over at the BLS and you can see that a great percentage of the population is employed today (59.8%) than at any time before November of 1978. If UBI was the answer it would have come about in the previous decades when fewer people were employed, not today. And certainly not during the 2008 bubble when this whole UBI theory started gaining traction.
But even if it were the case that jobs are going away, UBI still wouldn't be the answer. The idea that you can just give cash handouts to the whole population is silly. The GDP per capita in the US is about $50k. If you going to give everyone enough income, about $12k according the Dept. Health, that means a tax rate of 24% of GDP to pay for bare minimum of UBI. And that is on top of the 27% that the government currently taxes, which already doesn't bring in enough income to balance the budget. To balance the budget you would need to bring the tax rate up to the expenditure rate which is currently 41% of GDP and add UBI's 24% on top of that. By the time it's all said and done the government would account for almost 2/3rds of the entire economy; for a minimum UBI. If you want a UBI that allows for a little more comfort, say $20k, then the government would now account for 4/5ths of the entire economy. Who the hell is going to invest in an economy like that?
Never mind what a disaster it would be for the labour force. We know that the utility of income is marginal. A $0.50 pay raise means a lot more to someone making $10/h than it does to someone making $50/h. People today work for $10/h because that is a huge step up from nothing. But if everyone is getting a $20k/year free handout who is going to work for $10/h? $10/h is only $20k/year, that's a paltry marginal increase for having to work an extra 40hrs a week. So in order to attract workers, pay will have to rise, which means price of good and services will rise, which means the UBI will have to rise. You think big business is shipping jobs to China and India now? Just wait until the price of labour in the new UBI economy stabilizes.
UBI is a classic example of something that sounds like a great idea in theory, but in practice would be an unmitigated disaster.