The same happens with the flu. A person has an underlying condition and the flu will finish them off. The killer is the flu/covid. Not the underlying condition.
No, a lot of those underlying conditions will be triggered by something or other within a few years.
I am going to tell you a secret:
Nobody lives forever and the human body reaches a point where death is coming sooner rather than later. It isn’t always fair and some people are quite young when they get to that point.