Not everything is about money. People were doing it, so they clearly had a motivation of some sort. I'm sure that some folks did it for themselves - just like writing a diary - but many others wanted to make new friends, earn praise, teach others, and so on.

If nothing else, LLMs have an indisputably negative impact on the second part. Fewer people will make it to your website if there's an AI digest on top of search results (or if they can skip search altogether by asking ChatGPT).