I wonder too. It might be that progress on the underlying models is going to plateau, or it might be that we haven't yet reached what in retrospect will be the biggest inflection point. Technological developments can seem to make sense in hindsight as a story of continuous progress when the dust has settled and we can write and tell the history, but when you go back and look at the full range of voices in the historical sources you realize just how deeply nothing was clear to anyone at all at the time it was happening because everyone was hurtling into the unknown future with a fog of war in front of them. In 1910 I'd say it would have been perfectly reasonable to predict airplanes would remain a terrifying curiosity reserved for daredevils only (and people did); or conversely, in the 1960s a lot of commentators thought that the future of passenger air travel in the 70s and 80s would be supersonic jets. I keep this in mind and don't really pay too much attention to over-confident predictions about the technological future.

I mostly mentioned Claude Code because it's what Mitchell first tried according to his post, and it's what I personally use. From what I hear Codex is pretty comparable; it has a lot of fans. There are definitely some differences and strengths and weaknesses of both the CLIs and the underlying LLMs that others who use more than one tool might want to weight in on, but they're all fairly comparable. (Although, we'll see how the new models released from Anthropic and OpenAI today stack up.) Codex and Gemini CLI are basically Claude Code clones with different LLMs behind them, after all.