Indeed! Many of them are just copying and pasting answers out of laziness or because they don't know they're not supposed to. But you know what? That's okay! It doesn't matter. And it's all thanks to the magic of large-scale ranking! Let me explain.

If we had a LLM that just "reads" text indiscriminately, we would end up with a model that could hardly be better than the average human (...as the average human is just, the average). However, the moment we have multiple answers per question, and hundreds of people upvoting/downvoting, and ranking them relatively according to their quality (...and a few moderators like on reddit), we end up with a set of fairly high-quality question-answer pairs that are better than the average human answer, in the same way that a set of weak classifiers can result in a strong classifier (i.e. AdaBoost).