The problem with this theory is that AI-generated writing is just now hitting the mainstream, and it's only been in the past few years that AI-writing has gotten somewhat competent. GPT-1 was created back in 2018 and, while impressive, it was extremely easy to tell that it was a bot. Things are approaching a tipping point now, but until ChatGPT at least, it's just been cheaper and easier to hire some poor freelance writer a couple hundred bucks to shit out an article about whatever's trending on twitter than to have an AI write it and then edit it to pass scrutiny.