So John asserts “ But it is important to understand the barista is not creating wealth. She is providing a valued service for sure”, denying the contribution of labour [or labor if you prefer] to the creation of wealth.
UBI is a response to the automation of the productive functions within the economy, which leads to the situation in which fewer workers are involved in creating the goods and services demanded by consumers. Craft beer is labour intensive, but most beer consumed is made in large plants where fewer workers per hectolitre are required now than in the past. The wealth created by that brewery is then distributed to owners/shareholders and concentrated within a smaller number of households. This concentration creates economic imbalances and grants undue political power through PACs and other contributions to candidates. A good example is the recent round of tax cuts in the US, which benefit only that very investor class among the 1% of wealthiest US citizens.
UBI, and social services in general, redistribute that concentrated wealth [in the form of money, to follow this paradigm] and creates a more inclusive and cohesive society, rather than dystopian disparity.