I heard an evolutionary explanation for snoring -
The explanation was that it is an advantage for hunting animals to sleep and wake together. So snoring is a signal to the pack that everyone needs some shut eye. Then the pack will wake together and hunt as a pack more effectively.
This seems reasonable to me and fits two other aspects of snoring. 1. It is catching, which it would have to be to get the whole pack sleeping. 2. It is animals that hunt in packs that snore - dogs, lions, humans.