Just to be clear, the people engaged in this discussion with any degree of seriousness think... LLMs (large language models) are going to get us there?
I normally would, but in this case, I simply don't know where to start. The counterargument is that LLMs just don't shift the graph on productivity remotely enough to entertain this level of doomerism.
Now, it may be that people are extrapolating comparable, but non-LLM successes in AI based on our current "AI" cultural moment, but if that's the premise, I wish that were made a little clearer.