What was the natural dose?
Was it mild or severe?
Did it really happen or just assume it was COVID and not something else?
Was that dose studied to understand if it was sufficient?
Was the variant of infection enough to elicit a broad response to other variants?
I don’t doubt some natural infections are good enough. But there are a lot of variables to just assume they’re all good. Getting the vaccine gives someone a controlled and standard dose with it’s studied response.
We don’t base policy on “might be good enough”, but on known responses.