5 years? Bit of a long stretch with how much focus is going into AI. I’d be surprised if it’s not possible within two iterations of the new iPhone.
By all accounts GPT-3 is wildly inefficient in resource use; OpenAI runs like a company that’s concerned with the functionality it can achieve by calendar date, and has an almost infinite bankroll to do it. But, other actors in the field have different priorities, and the various open source or, at least, available-to-use models seem to be far more efficient than the OpenAI models of similar function (though they are behind the newest OpenAI models in function.)