As promised, they released GPT3.5 fine-tuning today. They opened GPT4 API access a few months ago. In a few months, they'll release GPT4 fine-tuning.
Many favor open source AI, and criticize OpenAI for not being open enough. But the most important thing is, OpenAI innovates. Fast.
Llama, Bard, FB's open source stuff is good but it's lightyears behind OpenAI. You have to credit them for that.