My Dad caught covid two weeks ago and was sick for one day. He got his booster shot about a month before testing positive.
My Dad's friend caught covid three months ago and just got out of the hospital this week after experiencing severe breathing problems and covid related inflammation of the heart. He never got vaccinated.
They are both the same age and in the same general physical condition. I don't think one anecdote will change anyone's opinion at this point, but imo the lesson is clear.