With content from humans, there has to be sufficient motivation to produce a significant quantity of coherent garbage (since it takes time and effort) which means that you can trust by default because intentionally generated garbage is rare unless the topic is one of the niches where there is motivation for it (e.g. politics, history related to politics, and sales). Like, sometimes people do put in exceptional effort to fabricate something as a practical joke, but that is sufficiently rare that you can ignore it in your daily life.
Without AI-generated content, cookie recipes would be "safe" from that, since only people who care about cookies would bother to write up articles about them - but now you suddenly have to mistrust all sources of all information, which is a new thing.