If the users chooses what they are shown and the order they are shown in, then it's fine. If the platform chooses, then it's not, because they will always choose what creates the most engagement.

So HN should be banned

Not necessarily. Just fix the algorithm. Showing all submissions by time should be ok, showing all submissions by number of upvotes should be ok if the user chooses that.

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The platform can also add ghost upvotes and downvotes and censor upvotes and downvotes.