Apples and orange trees

Them: Cancer and heart disease EACH killed more people in the US last years than Covid.

Experts: Heart disease is a blanket term for a cluster pf approximately 30 different deadly illnesses. Cancer is a blanket term for a cluster of over 100 separate diseases. Another common comparison is Flu, which is a blanket term for about 60 different illnesses.

Covid-19 is one disease. No single strain of Flu, no single type of heart disease, and no individual cancer come close to the casualty rate of Covid.

The sort of comparison you're making is called an ecological fallacy. Which means you're comparing statistics across two very different and incompatible levels of analysis. A comparable situation would be if I said, "Wow. New York has a lot of people." And you replied, "Actually, Asia has a lot more people than New York." Technically true, but you're comparing a city to a continent, which is dumb. Same thing if you compare one disease to a group of a hundred.

But that's the thing. Covid is so bad that people who don't realize this, feel a natural compulsion to compare it to something like cancer. That's how many people it's killing, that it's in the same ball park as all 100+ cancers or all 30+ heart diseases COMBINED.