While I disagree with the counter position I do believe it to be an honest account of their experience. I think the counter intuitive aspect is that marginal cost of software is practically zero so in an efficient market the consumption of it will be dominated by the best software written by senior devs with AI, even if the production of software is dominated by junior devs with AI. I think we are in a transitory phase where still employed juniors can be very productive shortly before becoming unemployed at which point that productivity drops to zero. If junior devs are productively producing software that then goes unused then how productive were they really. But I understand that the latter effect may not have been picked up in the general stats. Anecdotally again, I fired 3 juniors and went solo and I know of many others who have done something similar.

Another aspect is that once the easier work is complete then the remaining residual is the difficult work, and this changes the relative productivity to the point where a junior developer may not be able to make any further progress at all.

Overly bureaucratic companies tend to generate easier work for themselves to the point that this work dominates their total workload. If we are to measure productivity by opening and closing Jira tickets then I would expect the junior developers to get a much bigger ‘productivity’ benefit from AI than senior developers.