As a relatively new senior developer who has witnessed the emergence of Copilot while progressing from Junior to mid senior and above, I completely disagree with the premise.
Junior developers have huge gaps in their knowledge, which they fill naturally by working on different parts of projects and getting their hands dirty. What's actually happening now in my company is that juniors who have been primarily using LLMs to code have a much worse grasp of the codebase, the tech stack and software engineering in general than those who don't, even if they deliver faster. Also, in a complex codebase, the number of mistakes they produce doesn't go down with time, because they're not actually learning from their previous mistakes and applying the learnings.
As a senior developer who used to use Copilot heavily, I have to admit it's a crazy performance boost when you're adding critical small changes here and there, across different codebases with different stacks, when you know what you want to do. However, I recently decided to stop my copilot subscription and go back to non-assisted coding, for multiple reasons:
1. Coding is fun
2. On a senior level, mistakes are more problematic.
3. Writing the code yourself results in much higher quality code, for me, than reviewing the LLM's code
In short, I disagree with the article