It existed before, it just wasn't well known. Early 2023, it became publicly available and took the world by storm and everyone sorta freaked out. The current array of LLMs are artificial general intelligence. That's not a real popular stance to have, but this debate is absolutely lousy with hype-trains trying to get rich quick, laughable hollywood tropes, the next wave of Luddites who kinda have a point, and buzzwords getting new definitions faster than anyone can learn what they mean.
But before anyone tears into me for dissenting, you have to remember that any human with an IQ of 80 is most certainly a natural general intelligence. If that blows your mind or you have some sort of knee-jerk "but this is different" sort of reaction, then you've got some misconceptions about the term "AGI". It doesn't mean the thing is a god. It doesn't even mean that it's particularly smart by human standards. A general intelligence can be REAL dumb and make all sorts of mistakes and still most certainly be generally applicable. If you actually wanted to talk about some god-like all-knowing machine that has "woken up" and must hunt Sarah Conner... I just don't care. That's lazy soft sci-fi drama. Use a better term that actually has the meaning you want. Skynet or Omnissiah or or Landru.
GPT is certainly artificial.
It displays some level of intelligence. But that bar is REAL low. Ants have some intelligence. White blood cells and Amoebas display intelligence, even if they're just following their programming. ELIZA displayed some level of intelligence, even after you spotted it's tricks. The intelligence of a goomba can be explained with a single "if" statement and that still counts. The fact that this trait that we are able to measure can come in very small sizes does not mean anything that isn't god-like isn't intelligent. We wax poetical about the sanctity of life while ignoring the billions of gut bacteria that we kill all the time and they are most certainly living biomass.
The real crux is that GPT can generally chat about anything. It's not very good at a whole lot of stuff, but it can try. (a big failing of it's part is that it fails to be answer uncertainly when it's just making stuff up. It's confidently wrong.) The reason that so many people used the Turing test as a means of judging if something was a general intelligence is because natural conversation can generally cover any and all topics. The thing would have to be generally intelligent if it could consistently pass a Turing Test and be mistaken for a human (at least as often as humans are). That was the goal-post circa 2010. And it was there for a good solid reason. I've failed to hear any good reason that goal-post needs to move.
And if you want to talk about artificial SUPER intelligence... remember than anything displaying an IQ of 101+ could technically be considered super-intelligence. Which has probably already happened although tests for AI has it's challenges