Having good heuristics to make quick judgements is a valuable life skill. If you don't, you're going to get swamped.

> Would any of that somehow be more worth reading if the author posted a video of themselves carefully typing it up by hand?

No, but the volume of carefully hand-typed junk is more manageable. Compare with spam: Individually written marketing emails might be just as worthless as machine-generated mass mailings, but the latter is what's going to fill up your inbox if you can't filter it out.

> If LLM output were never worth reading, ChatGPT would have no users.

Only if all potential users were wise. Plenty of people waste their time and money in all sorts of ways.