Perhaps the reason that they didn't release the specifics of GPT-4 might be in part due to them wanting to be able to charge a decent amount and make a much larger profit than before. I've tried GPT-4 and so far haven't found it to be so much better than previous models. Some sources claim a 10x increase in ... well I don't know what exactly tbh. How do you even measure it? The opinions on this seem to differ a lot, depending on who you ask. By performance on standardized tests? That doesn't necessarily seem like the best metric for what the LLM tries to be.