AI was trained on human writing. If it produces a certain tone, then that's probably a result of the material that was favoured in training it. That construction was common in human writing before it became common in AI too.

What makes it stick out is when AI uses it in contexts where humans normally wouldn't, but this kind of assertion is common in scientific papers and articles. It would make sense to train an AI on scientific writing, since that tone sounds authoritative and like you have some idea of what you're talking about.

So I don't think this is an LLM-construct; it's an instance of the original style that LLMs copy.

I'd like to see a study on that, I see it mentioned so much it's almost achieved meme status.

It could very well be a Baader–(👀)Meinhof phenomenon.