Agreed - the circumstances indeed changed, and the possibility of automatically generating code from a natural language prompt is something we didn't have ever before.
As an Emacs user, I can testify that it's a game-changer. Codex CLI paired with `emacs --batch` is perfectly capable of setting up, developing, and testing just about any kind of extension you'd want. And with packages integrating LLMs into Emacs, you don't even need an external harness - open a buffer, type a prompt, get a useful extension or customization. It really works quite well.
But I stand by my opinion: Emacs is just one piece of software, not completely unknown, but rather niche, all things considered. Almost no other app supports seamless extensibility at Emacs' level (not even web browsers come close, and not by accident - it was a conscious decision to drastically limit what plugins can do).
Most programmers don't feel the need to make their apps easily and deeply extensible. Most users don't feel the need to extend their apps - even simple customization is rare. Most product owners don't want users to have "too much" freedom to change things.
So, while LLMs do give us a realistic path towards making extensible/malleable software attractive to users, almost nobody is taking that path right now. Realizing LLMs' potential in this area requires large parts of both the user and developer populations to recognize the possibilities and then actively pursue them for a few years. For now, it doesn't look like anything like that is happening.