Earlier quoted context omitted.
"A perfectly free market" is essentially a deliberately vague pseudoreligious concept. No true free market would [ insert as appropriate ].
It's not really that vague. The less resource allocation is affected by non-market forces, the freer the market. Of course, a perfectly free market is not actually possible. My point is moreso that there are extremely good reasons to limit the autonomy of markets.
Unions? Monopoly power? Government enforcing contracts? Government competing in the market? Natural disasters? Normal weather? Taxation? No taxation? Strong property rights? No property rights?
A "perfectly free market" is a meaningless phrase dressed up to sound like "frictionless in a vacuum". It exists for the purposes of cynical lobbying.