It definitely makes a huge difference to have savings if you want to be an entrepreneur. But these days, a decent programmer can save up a year or more of runway and build industry connections just by working for a few years and not spending outlandishly. If the startup doesn't work out, a new cushy job is waiting for you.
So yeah, startups are risky and favor the wealthy, but let's not overstate the case. I'm in favor of basic income and I agree it would be a boon to entrepreneurship, but people with the skills to build a tech startup have already won the lottery. We're not the ones in need.