I don’t think they “got lucky”. nextjs is an old project now, and for a long time it was the simplest framework to run a React website.

This is why most open source landing pages used nextjs, and if most FOSS landing pages use it, then most LLM’s have been trained on it, which means LLM’s are more familiar with that framework and choose it

There must be a term for this kind of LLM driven adoption flywheel…