Does the marketplace of ideas work?

The marketplace of ideas has a naive view of social progress

Question: Does the marketplace of ideas work?
Position‹2 of 3›: No, the marketplace of ideas does not work
Argument‹4 of 4: The marketplace of ideas has a naive view of social progress

If it worked, society would not repeat its mistakes. That alone is proof that the idea has no legs to stand on.

The argument

Those who do not learn from history are doomed to repeat it. Even when presented with proof that one idea is more effective than another, the same arguments arise again. This is deeply problematic in the context of society. If all opinions can be shared at any time, there is nothing to stop the emergence of a new slavery lobby, the legalization of human trafficking, or other insidious practices that have been rightly criminalised. Censorship of ideas that society has collectively condemned, is necessary for social progress.

Premises

[P1]Even when one idea is proven more effective, the same discredited arguments resurface, so society fails to learn from history. [P2] If all opinions can always be shared, nothing stops the re-emergence of rightly criminalised practices such as a new slavery lobby or the legalisation of human trafficking. [C] Therefore, because it holds a naive view of social progress and requires censorship of condemned ideas, the marketplace of ideas does not work.

Counter-arguments

Western progress in civil rights, economic principles, and liberty show that when opinions are given air to be debated, the truth almost always prevails and humanity moves forward. Sound arguments and truth languish without alternatives by which they can be compared. Giving government the power to outlaw ideas deemed subjectively wrong threatens free speech. John Stuart Mill supported the notion of continually giving wrong opinions a stage so that the public might gain a “clearer perception and livelier interpretation of truth”.

Rejecting the premises

[Rejecting P1] "Society fails to learn from history" is asserted rather than shown, and the premise's own framing works against it: that a discredited argument can be raised again does not mean it prevails again, and the marketplace's defenders would say recurrence is exactly why the refutation must stay in circulation. [Rejecting P2] The examples are the weak point rather than the strong one. Slavery and human trafficking are prohibited by law, and it is enforcement rather than the suppression of advocacy that prevents them, so the premise never shows what censorship would add. The conclusion also changes the subject: that the marketplace needs supplementing by law is compatible with its working within its own domain, which is what the position denies. And the argument nowhere says who would decide which ideas count as condemned — the objection the counter-argument raises, and the one on which this whole position turns.