quick one - how long has chatgpt been around?

The models underneath are older than the chat app. GPT-3 was open to developers from 2020, so a few marketing tools were quietly built on it before ChatGPT made the whole thing mainstream.

Public launch was the end of November 2022, so coming up on four years. If the proposal is leaning on how long it has been around, that is not really the question - ask them what they intend to produce with it and who checks it before it goes live. That is where these things come apart, not the vintage of the model.