No, they're like an extremely experienced and knowledgeable senior colleague – who drinks heavily on the job. Overconfident, forgetful, sloppy, easily distracted. But you can hire so many of them, so cheaply, and they don't get mad when you fire them!
Individual sentences and paragraphs may mostly work, but it's an edifice built on sand out of poorly constructed bricks plus mortar with the wrong proportions (or entirely wrong ingredients).
LLM output is "truthy" - it looks like it might be true, and sometimes it will even be accurate (see also, "stopped clock") but depending on it is foolish because what's generating the output doesn't actually understand what it's putting out - it's just generating output that looks like the kind of thing you've requested.