I find it frustrating how people can blithely claim free markets are broken in all sorts of ways without actually showing even a single example beyond the well-known case of externalities.
There are other major problems. Free market theory assumes that producers have no fixed cost, which means their expenses would be zero if they produced nothing.
That breaks as soon as you introduce workers in the system. Maintaining workforce comes with a huge fixed cost. Workers must be paid enough to survive (food, shelter and health care), and since they die at some time, they must be renewed, which means new workers must be trained.
If you attempt to let the market invisible hand handle that, you may hit situations where your workers cannot survive and be trained, which is obviously a problem for producers. And moreover the worker is often also a consumer: if the labor market makes workers too poor, you get an overproduction crisis.
But I am just telling obvious things, as in real life, free labor markets do not exist in developed countries. Slavery and child labor ban are an obvious regulations, for instance. The point is that it introduce regulations in any market that involves labor.