Viruses don't "want" to do anything, as they lack the capacity for any type of cognitive awareness. Not all viral infections are fatal. When someone dies as a result from viral or bacterial infection, it's not necessarily the germ that's killing them, but the symptoms caused by said infection. If an infection causes inflammation in your lungs and you cannot breathe as a result, you die from asphyxiation. There's no "will" or "desire" from the virus, it's just how your body responds to a given infection.

NOTE: I am not a doctor, virologist, epidemiologist, or any other type of expert in this field. This is simply my understanding based on reading literature published by experts in the field. I'm sure I got some nuances and/or terminology incorrect. You'll probably get better information reading peer reviewed research rather than asking random people on the internet.