Had I had a relatively small UBI of perhaps $12,000 per year, I could have met expenses long enough to get ahead of the curve. I wouldn't have spent that time burned out and getting sucked into dead end $20,000 per year jobs that took all of my time and energy.
So for me, not having a UBI and throwing away a rather prolific 20 something probably cost the US GDP growth whatever my business might have contributed for a decade, say whatever a typical game developer salary might be (perhaps $60k/yr), call it $600,000. That could easily be 2, 4, 10 times that much if we grew enough to hire other employees.
By not investing in the workforce like the country did with public works before the information age started in 1980, my generation (gen x) lost out on at least a 5x rate of return. My struggles happened just before Prosper and Kickstarter got big, so I ran up staggering credit card debt. Had we chosen a more progressive route, even at a 20% tax rate I would have paid the government back what it paid me, with the bonus of life sucking a whole lot less.
I think a UBI might be one of the few things that can raise the 10% startup success rate because it attacks burn rate directly. It would also allow startups to focus on things more meaningful than video games and social media apps because it wouldn’t just be about trying to get enough F.U. money to get left alone anymore. I had always planned to save enough to be able to work on AI and alternative energy, and now with consistent hard work I have a chance of doing it, but with a middle aged realism that is just not helping my motivation. To be 20 again and told “go do all the things” is one of my deepest wishes and I hope it happens for future generations.