If you have to accept a pitiful wage in order to barely subsist, that is effectively forced labor. In practice, the only alternative is to starve. Which is why a labor market without basic income or some other kind of safety net is not a free market at all.

Not everyone can learn everything, but even if that were possible, if everyone in the world knew e.g. how to code decently, coding would be a minimum-wage job too. There is just not enough demand for jobs to make everyone valuable, and automation is just making this more pronounced.