There is a critical focus in the article on algorithmic improvements. Much harder to measure and predict, but I think there is a good case to be made that recent progress has not just been quantitative.
I agree that there's a focus on algorithmic improvements, but what is the basis for assuming that we'll be able to continue to make algorithmic improvements on the same scale? The argument feels exactly backwards - if you had a deep understanding of the field, then you'd be able to discuss the untapped areas of potential algorithmic improvement and use that to predict future progress. The argument in TFA uses the trendline of past progress to predict untapped areas of algorithmic improvement.