No, it hasn't. It has made great strides in certain directions, but is woefully deficient in others.
For one thing, for as impressive as it looks, it's really quite difficult to use it. The "knowledge" it has about text isn't an obviously usable understanding of the grammar and some other symbolic representation of the information that can be used by other technologies, it's more a self-referential knowledge embedded in opaque neural net values that can almost only be used to extend the text. That is not 100% true, but using it for anything else is really hard. I would expect a technology that has "solved" the language processing problem to be useful for a much wider variety of topics, to be, for instance, something I could hook up to the Unix shell to provide a safe and reliable human language interface to it.
(Note that prompting this model for some shell commands is light years from what I mean; along with the dangerous unreliability of the resulting commands, it also isn't actually hooked up to your shell and operating in a space where it knows your directories, files, and their contents. I want "give me a list of files relating to my business deals with Comcast" to literally work on the shell, to the point the result could then be piped to some other plain-text request, not what ChatGPT can do.)
"Its responses are fluent and rapidly becoming indistinguishable from human output."
Again, in some directions.
"It’s often bullshitting, in the sense that it’s convincing prose often turns out to not reflect reality."
While I acknowledge the second clause makes your sentence accurate on your terms, I still would say it's a better way to think of LLMs that it is always bullshitting, always confabulating. It's just built in a way that the maximum-probability confabulation of a factual topic may happen to be the fact. I mean, if you think about it, that shouldn't seem that surprising a statement. I've done it myself in real life, just accurately guessed a fact I didn't really know. Less often than I've been wrong when making such guesses, of course, but it's still something not outside our experience range.
But it's not like the LLM in any sense "knows" when it is telling the truth and "knows" when it is bullshitting. You can get spun into a real philosophical tizzy about what that "knows" means, but it doesn't matter, because for any sensible definition this particular model doesn't "know". It isn't built to "know". It just spits out the maximum probability continuation. This is not a claim about all AI architectures, it's just about LLMs. They don't know. Even if you convince one to output that it doesn't know, it doesn't know that either, it just thinks that's the most likely logical continuation. While this may be surprising to anyone who has been on the Internet for a while, there are in fact samples of people saying "I don't really know" on the Internet that would have worked into the training data.
I will say this; I think GPT does serve as the final refutation of the Turing Test as a measure of AI. It turns out to be entirely possible to build an "AI" that is basically optimized to pass it, yet, strangely incapable of almost anything else we would consider an "AI" to be.
I'm actually much more impressed by GPT than I sound on HN. It is a legitimately interesting technology and very impressive. The problem is, the Gartner hype cycle has massively overshot the degree to which it is interesting and impressive, so I sound very down on it as I try to bring people back to Earth. I keep going back to the video game metaphor... video games look far more interesting and complex than they often actually are, because the graphics can look so amazing and awesome and we've made such exponential advances in that field over the past few years that we can forget that the state of the art in, say, NPC dialog, remains the "choose your own adventure" dialog tree that was a familiar staple in games for over 30 years now, with the only elaboration since then being full speech voice acting (by humans). ChatGPT is the video game graphics of the AI world. Still impressive on its own terms! It's amazing what we pump to our screens at 120Hz/4K with the right hardware... yet, what is behind those graphics is nowhere near as impressive. Similarly for ChatGPT. Very impressive! But it's a munchkin that dumped all its stat points into "sounding good to humans" but doesn't have hardly any stat points anywhere else.