I've said it before but no one takes it seriously: LLMs are only useful if you're building something that's already in the training set ie already commodity. In which case why are you building it???
The obvious point that you're missing is that there are literally infinite ways to assemble software systems from the pieces that an LLM is able to manipulate due to its training. With minor guidance, LLMs can put together an unlimited number of novel combinations. The idea that the entire end product has to be in the training set is trivially false.
It's not that the product you're building is a commodity. It's that the tools you're using to built it are. Why not build a landing page using HTML and CSS and tailwind? Why not use swift to make an app? Why not write an AWS lambda using JavaScript?
Historically big AI skeptic here: what you say is very not true now. LLMs aren't just regurgitating their training data per se. I've used LLMs on languages the LLM has not seen, and it performed well. I've used LLMs on code that is about as far from a React todo app as it's possible to get.