Because I like to save time?
I can do all of this myself, but why would I waste 1-2 hours (per model) on doing all that myself if I can just instruct some stupid LLM to do it for me? It's repetitive boilerplate.
This is a weird thing to point out. I've always had to look up how to start a project even before LLMs, even with years of experience. With React there's vite, React router, nextjs, tanstack. With nodejs there's Koa, hapi, express, and tons others.
Most fullstack engineers are likely not starting a lot of new projects at work, and may only be doing it a few times for side projects, LLM or no.
Edit: Incidentally, I tend to treat "code made by an LLM" and "external dependencies" pretty much the same. Pretty low trust, with a strong interface between it and any code that matters
I usually only use stuff that either is raw Js, HTML, CSS or whatever builds on top of it. Never something that introduces some DSL and generates files for said environments.
Ah, let me guess / you're one of those non-technical PMs who can finally shove it to the devs - by spitting out unreadable HTML storing all it's data in a flat file? Oh boy, do I have news for you...