Look at global trade. The Western Empire controls the all the markets. There is no free market, unless the US collapses and no other power hijacks the market after them.
There is no markets with zero control, sure. That does not mean there isn't a free market though. If you can only have idealism, or nothing, then expect a life with nothing.
Darknet markets and OB can be considered free markets, but they are a niche currently.
Even black markets can not be considered free markets since they have to operate outside the law. If they didn't have product seized so often then they might be closer to a free market
