>In fact, they were fairly useless when they modelled the source distribution, that's why ChatGPT was an instant hit whereas GPT-3 was mainly only interesting to other AI reasearchers.

I had a bot which used the original GPT3 (i.e. the completion model, not the chat model) and its answers were pretty decent (with the right prompting). Often even better than GPT3.5, whose answers were overly formulaic in comparison ("as an AI language model...", "it's important to ..." all the time)