Like all tool improvements in software engineering do, LLMs simply increase the demand for software as fast as software engineers can step up to use the new capabilities provided by tools. This is not a closed world and it's nothing new. It's not like we're all going to sit on our hands now. Improvements in tools (like LLMs) enable individuals to do more and more complicated things. So the complexity of what is acceptable as a minimum simply goes up along wit that. And this will allow a wider group of individuals to start messing around with software.

When the cost for something goes down, demand for that thing goes up. That fancy app that you never had time to build is now something that you are expected to ship. And that niche feature that wasn't really worth your time before, completely different story now that you can get that done in 30 minutes instead of 1 week.

Individual software engineers will simply be expected to be able to do a lot more than they can do currently without LLMs. And somebody that understands what they are doing will have a better chance of delivering good results than somebody that just asks "build me a thingy conforming to my vague and naive musings/expectations that I just articulated in a brief sentence". You can waste a lot of time if you don't know your tools. That too is nothing new.

In short everything changes and that will generate more work, not less.