If automation improves productivity by two times, it means that people have to work half as much. Simple math. Why is this not happening with the glorious free

If automation improves productivity by two times, it means that people have to work half as much. Simple math. Why is this not happening with the glorious free market capitalism? I once brought up the idea of automation tax and UBI here and was downvoted to oblivion by the HN conservatives. But that’s obviously the only way to avoid modern day slavery or else we end up in a local equilibrium where the owners of capital automate away every thing that gives the masses their edge and we put the final nail in the coffin of democracy. (Not that we are too far from that with the media, legislation, election laws and enforcement being massively biased towards capital controlled by a small minority)