AGI is fairly easy to detect for this reason. Does this system make a majority feel you don't have to hire people anymore? If not its not AGI.
Solves what? Chess? No thats not AI, its just a chess bot. Turing test? No, thats not AI, its just a dumb token predictor.
Why would the goalposts stop moving at AGI? I am 100% convinced it will somehow still lack the "gusto" or the "taste" or the "timbre" of real intelligence. You can see it in coding right now, AI has bad "taste" in coding, because really, we can't do a better job critiquing that which is obviously (on occasion) just plain good.
You are moving the goalpost here if you think the chess AI was AGI. All those problems were evidence AI wasn't as smart as humans, not goalposts determining when AI is as smart as humans. The first turing test winner wasn't even an LLM, it was an expert system, so we already knew that test wasn't enough for AGI.
If I want my ox-cart to fly, I need to add wings, but that's probably not all that needs changing.