However what this viewpoint doesn't account for are team dynamics. A strong TL can turn NNPPs into incremental positive contributors. A great programmer without leadership capabilities will not be able to outpace the technical debt. There are also more subtle dynamics depending on the structure and personality traits of the individuals. Ultimately programmer productivity is not an absolute value, it depends on the whole ecosystem (including other functions, leadership stance, etc). After doing this for 25 years (IC, TL, EM, CTO), I strongly believe a healthy team is about harnessing and orchestrating different individuals unique strengths rather than trying to set too high a bar—the latter will lead to counter-productive competition and ultimately burn out your best folks.