not just money. How are you going to support this client’s support ticket if there is no log at all?

Don't. "We're unable to provide support for your request, because you disabled retention." Easy.

You can still provide support too if you want to. You just need to ask the user what their query was, what response they got, and what response they would be expecting. You can then as the expert either spot their problem immediately, or you can run the query and see for yourself what is going on.

Sure it is a possibility that the ticket will end up closed as “unable to reproduce”, but that is always a possibility. It is not like you have to shut off all support because that might happen.

Plus many support requests are not about the content of the api responses but meta info surrounding them. Support can tell you that you are over the api quota limit even if the content of your prompt was not logged. They can also tell you if your request is missing a required parameter or if they have had 500 errors because of a bad update on their part.

They don't care, they still want support and most leadership teams are unwilling to stand behind a stance of telling customers no.

... but why is not responding to a request for zero retention today better than not being able to respond to a future request? They're basically already saying no to customers who request this capability that they said they support, but their refusal is in the form of never responding.