"He notes that a more infectious virus is more dangerous than a more lethal one, “because every new case will infect more people, and each of them will infect more people, such that the number of cases will grow exponentially.”"

Oh my god, that sounds horrible - except, that's how EVERY infectious disease works. We have been living with that kind of diseases forever.

Also, no, they don't grow exponentially. The population saturates.