Too imprecise
'Software developers' is far too sloppy and imprecise. It's like 'gamers', which encompases people just happily doing hidden object games, rabid animals doing PvP MOBA, people running around solving problems in The Witness or Baba is You, people RAIDing in MMOs, and people building CPUs in redstone.
On the 'software development' side, I'm sure if you're a code pig (a giant corporation programmer stuck in a cubicle/pigpen mindlessly pounding on a very limited task) LLMs will help a lot, because you're not doing much thinking to start with. Might as well just steal the code of everyone else who's done this before, which the LLM has already eaten, digested, and shat out. Lots of room for time saving here.
If you're an actual engineer, LLMs can't help with any of the actual engineering jobs, because those are tradeoffs between the requirements, the desireables, and the consequences and resource tradeoffs of each approach. An LLM has no f@#$ing idea at all about any of that. It will happily give you O(N^3) code which ignores the requirements, because hey, it compiles. Though based on my recent playing around with Llama code helpers, even 'it compiles' or 'it does the right thing' isn't guaranteed.
Basically, no LLM is 'thinking' at all. It is stochastically regurgitating all the things it has seen before. So the more your job involves actual thinking, and the less it involves going on StackExchange and copypasta-ing code snipped and randomly smacking them till they compile, the less threatened you are. And the less LLMs can help you. Like I said, I've been playing with this, and the best it can do for me is a line or two of auto-completion (and it's wrong at least half the time).