No, we've barely scratched the surface. Billions of dollars have been poured into the stupidest possible thing that could work + scaling, and we're only now trying more clever things. Fine-tuning on specific tasks will yield considerable productivity benefits in those domains.
I'm not only skeptical of your claim on the "rate of improvements over the last 6-12 months", but it's not even a compelling time horizon to infer any kind of trend at this stage.