Because the "rate of improvement" is only astonishing in well understood areas and really only astonishing if you yourself are not that great at what you do. Speaking for myself here, my job is extremely safe given that my boss doesn't wanna sit there and prompt AI all day and i work in a fun little 4 person company. We already have plans for the 3 next years which involve me :-)
This is a bold vague claim many on HN make, but never put back-of-napkin numbers on. e.g. do you think agentic Opus 4.7/GPT 5.5 are 95th percentile coders but you're 98th percentile? Or are you saying you're a middle-of-the-road 60th percentile coder and AI is 20th percentile so only 20% worst programmers should worry? Let's be specific about the claim being made.
Do you have examples of (almost) entire software written by AI?
AI excels at make toy versions of software, prototypes and skeletons.
The closest things to fully functioning software created by AI that exists are all done by people that are experts in that particular field, ie software engineers.
If you mean a human has to provide the initial impetus or spec, then no, there is no software in the world entirely written by AI.
If you mean a human provides the impetus or spec and an AI takes care of the rest, this is happening. But it is expensive so this is only really happening at FAANGs and whatnot.