How do you start a business for a product for which there is no demand? Not as in “didn’t know I wanted it” but as in “can’t pay for it “.
That said, I’m not a fan of UBI. Yes, do tax the hell out of people who made fortunes from their inherited wealth and social connections / status, but use the money to hire people to do something useful and purposeful. E.g., roads, parks, schools, healthcare, basic research.
Maybe we try old fashioned Keynes style policy again, as Reagan / Laffer nonsense seems to have objectively failed for 90+ percent of the population, then maybe we discuss UBI if still needed.
Edit: P.S. I mostly like your comment, otherwise.