You don’t think much, do you? When was the last time a dead-out over winter get robbed out and resulted in the dispersal of the varroa mites?
Yes, you limited knowledge just tells about how much you think. Parasites do not set out to kill their host. It is self defeating if they die, along with the host.
Eventually, the mite and the bee must live together. If all varroa did was to kill off the host, they would not exist. I wonder where these mites came from, if there were no live hosts? The problem with varroa ia analogous to infecting Inuits with the common cold virus - it killed them in droves.
Contrary to what you might think, varroa is not going away. Treating has certainly been necessary over the last 25 years, but eventually - when humans have killed themselves off - the bees will need to look after themselves, without artificial chemical intervention. I think the colonies that continue to survive will be the ones that thrive.
On a similar note, perhaps beekeepers are just too greedy - they expect their bee colonies to return huge crops for their masters? A common fault of the human race. They are always wanting a better return from the animals and plants they have plundered. That was not the case when the planet was in better equilibrium.
Think about it. A little deeper than you clearly have done so far.
