this verse can be trying to explain something similar to that of Buddha back in the days.

the worlds desires and cravings lead to suffering due to actions to satisfy those desires. which can lead to death

in this verse I would say that nickleback is saying that if everyone cared and so on, then no one will suffer, therefore there would be no death, perhaps not physical death but maybe even emotional death. often people stop caring, stop loving, often people cry too much or lie too much, which causes pain and suffering to the person as well as those around them. therefore that pain being described as death. therefore if everyone cared and nowun cried, ect ect. there would be no death.

hope this helps

The lyrics you posted don’t seem overly deep or anything, at least not to me. Basically, it seems like they’re saying that people just need to be better to one another. Sort of a Golden Rule thing.