I run HomeAssistant, I don't get to play/use it every day. Here, LLM's excel at filling in the (legion) of blanks in both the manual and end user devices. There is a large body of work for it to summarize and work against.
I also play with SBC's. Many of these are "fringe" at best. LLM's are as you say "not fit for purpose".
What kind of development you are using LLM's for will determine your experience with them. The tool may or may not live up to the hype depending how "common", well documented and "frequent" your issue is. Once you start hitting these "walls" you realize that no, real reason, leaps of inference and intelligence are still far away.