[imjk]

It may be counter intuitive, but in some ways the opposite may be true. Viruses that are more deadly, are much less likely to cause massive pandemics like we experienced with Covid. When a virus is so virulent that it kills its host quickly and consistently, it dies off faster as the host doesn't have as much time to pass the virus to another host.

[actionfromafar]

But it could easily have killed children disproportionally and not the elderly, without changing much in its spread.