> In India, they still employ someone to sit on a chair in a lift pressing the button.
A culture of makework can be harmful in that it would push some people to do pointless jobs when they might actually do something beneficial for society (but perhaps not profit-generating) if they were given free time.
For example, I am fortunate to work remotely in a job that pays me a lot of money, but I am in a country with low cost of living. That means I only work 2–3 days a week. All the rest of my time I am busy with obsessively editing OpenStreetMap, writing the occasional journal publication in the field I trained in at university, and participating in the local arts scene as an audience or writer. I know that if I got to receive UBI, I would still be doing things with my time that are overall contributing to society. Please don’t make me sit in an elevator all day to press buttons instead.