I had heard (but now have trouble sourcing) that ChatGPT was commissioned after OpenAI learned that other big players were working on a chatbot for the public (Google, Meta, Elon, Apple?) and OpenAI wanted to get ahead of that for competitive reasons.
This was not a fluke of striking gold, but a carefully planned business move, generating SV hype, much like how Quora (basically an expertsexchange clone) got to be its hype-darling for a while, helped by powerfully networked investors.