For some reason, there's a thought-leader sect of Twitter talking about how good GPT-4 is, despite OpenAI having provided zero hints of what GPT-4 could entail or be differentiated from GPT-3/chatGPT.
They’re extrapolating from the performance of GPT-3.5. It’s speculative, but not anecdotal. GPT has improved rapidly over time, so it's not a huge leap to predict that GPT-4 will be even better.