My understanding is that the separation does help, but since the chat models are just fine-tuned text completion models, it doesn't completely prevent it. If I

My understanding is that the separation does help, but since the chat models are just fine-tuned text completion models, it doesn't completely prevent it. If I understand it correctly, the separation is a way for OpenAI to future-proof it, so that it can work fully once the models have an architecture that actually separates system, user and assistant prompts at a lower, more fundamental level. They specifically have a disclaimer in the API docs that gpt-3.5-turbo right now doesn't take system prompts into account as “strongly” as it should.