I feel that "soon" is doing a lot of the work here, as far as I recall back in 2018 people in the research community absolutely were expecting something similar

I feel that "soon" is doing a lot of the work here, as far as I recall back in 2018 people in the research community absolutely were expecting something similar to GPT-3, only the expectation was that these capabilities would land perhaps 2-3 years later than they did. And at least part of that was the (implied, natural, understandable) "linear extrapolation" of the total cost of compute applied - if your intuitive expectation of progress if effectively "oh, what would happen next year if we'd triple the budget" but actually the applied compute power increases hundredfold, then obviously the outcome arrives faster than you expected.