I think the confusion here is the word "dysfunction." If I get you correctly, you are seeing a health problem that occurs with age shouldn't be a dysfunction rather it should be considered normal, right?

I don't agree. The body system deteriorates as we get older but that doesn't necessarily relate to sexual dysfunction. And if something isn't working as it should it means something is obstructing its function, which means there is a problem there.

ED isn't restricted to men. Women too experience dysfunctional sex. And secondly, erectile dysfunction isn't caused by age. Young men below 40 experience it too. Lastly, most men who suffer from ED were the promiscuous ones or lived a reckless life in their youth, drinking, smoking, etc which caused internal damage resulting in the dysfunction in old age.

I'm yet to see a man who lived a healthy life with no life-threatening illness that has ED.