I have seen many many times in microcontroller forums posts from first timers in the liking of "hello sirs i have problem please show how to do this", followed by their own reply a few hours later asking again because they were holding up, where "this" was usually something really trivial, you just needed to read the docs and the rightful answer was "did you really not try anything in 6 hours?"
If hand coding pays better there will be plenty who can still do that.
More importantly I think, if devs become dependent enough on LLMs that they just put it aside when the model isn't available, they wouldn't be able to onboard quickly or at all.
It takes experience and a pretty deep understanding of programming in your language of choice to pick up a new code base and quickly understand how it works, the architecture(s) and pattern(s) being used, etc. Those skills would likely have been lost long before a dev simply can't work without the LLM.