For example lets look at janitorial labor, that is a hard job to automate and it is required in every business. So many would think that an increase to say $15/hr would just mean all the companies would just pay the same number of workers $15/hr right? No, what you would find it maybe instead of daily trash pickup it goes to 2 times a week, or employee's are asked to take their office trash themselves to a common trash bin. Common area's are cleaned less frequently, other employee's are asked to pick up some slack, and the janitorial staff will go from 10 workers to 6 , with a responsibility of 4 floors vs 2, or other such adjustments to the "acceptable" level of janitorial services.
The business has a budget of X for janitorial, that will not change very much simply because UBI or Min Wage came into play, they will just have to accept less janitorial services for the same money (aka inflation)