If this type of impact cardiac arrest happens from such an average tackle to a 24 year old nimble player, then we would be seeing deaths at every game. And it would have been occurring regularity in all the years football has been played especially during the years when they had less padding and crude equipment.
Can freak accidents happen? Sure but the trend of sudden death is up and it's noticeable. It's up for everyone but we only question it when its someone young or an athlete. If a sixty year old suddenly dies they say "well of course". Mass murder on a global scale. People refuse to see it because they might be scared of their own health for having already taken the shots. Worse tho, is the overwhelming guilt they might feel for dragging their kid to the doctor to get vaxxed. Rather than face that kind of pain, its easier for people deny it's happening and convince themselves that this is "normal" . Won't be able to ignore it forever tho