Because the scale involved. 13,200% increase in study of jab. By contrast from an article I found about relative heart problems in total US population from 2019 to 2020, there was an 11% increase. That 11% could certainly be due to other factors, for instance stress at losing one's source of income due to lockdowns. Loneliness. Isolation. Depression. But with an 13,200% increase...well come on.
Sorry. But that’s not proof. It could take time for the effects to kick in.
There should be data available among people with no vax, but having Covid. That’s the money comparison.