I agree. If I had a severe flu that didn’t get better after about five days, I’d see a doctor. They had the means to see one any time they liked.
Or call a “concierge” medical service to pay them a house call. They had the money. Most people in that echelon of wealth use concierge medical services.
My wife just got over Influenza A.
She was coughing/sick for a solid two plus weeks.
The worst I have seen her sick in our thirty plus years together. It was worse than when she had Covid.
She is 61. So, I can understand how it could become life threatening in someone with a weakened immune system.