How can it be a fact-checking machine when it can take nonsense and make a plausible sounding response from it? GPT has no understanding of what truth is (let alone any real understanding of anything)…
That's why I said "basic". It can tell me about the major philosophical schools and the corresponding philosophers if I am a newbie on the subject, but I wouldn't trust it for any deep "existential" or "metaphysical" reasoning.