Our culture ties self-worth to work. From CEOs to social workers, people get fulfillment and create their sense of self by seeing the impact they have while at their jobs, and we judge others based by the same metrics.
UBI can help people pay their bills, but poverty is a lot more than a financial problem. The communities where work is drying up are the communities most heavily affected by opioid addiction at the moment. Drugs are expensive--people don't get addicted because they lack money, they get addicted because they feel hopeless or lack a sense of purpose. Maybe government assistance can help hopelessness, but it sure as hell won't give people a sense of purpose.
It going to take a big shift in culture before UBI can really work out.