Coyotes do adapt but they aren't generally capable of taking down deer. But humans with guns are. As a hunter myself, shooting deer is a quick for the deer and good for the hunter in various ways, not all of which have to do with eating.
Are you suggesting that non-human predators cause less pain to deer than human hunters with guns? I highly doubt that is the case.
The ecosystem you speak of was destroyed when the apex predators were removed generations ago . Re-introducing predators does two things (look it up):
1) Disperses the herds thereby extending their range, and 2) causes some serious (unmanageable) peaks and valleys in populations of prey (rabbits, deer, moose, etc...) until equilibrium is reached (if ever)
Apex predator birth rate is low and it would take years to have a noticeable effect. Of course, releasing enough predators to "thin the herd", so to speak, requires an unsustainable predator population once the thinning is complete. So you get mange, starvation, fido goes missing, etc...
Hunters on the other hand only get as many deer tags as needed to control the populations. With that said, I agree that predators should be brought back in limited numbers and allowed reach natural sustainable levels within the ecosystem. But to use them as a short term way of controlling deer density is silly. You don't fix a complex, interconnected system build over decades with a band-aid.
In truth, this is all fairly removed from my original statement and intent, which was that if some hunters are no longer allowed to hunt an area and feel disgruntled, I have little sympathy.
Thus the vegetation can cope with loses as ever did and not just dies.
> causes some serious (unmanageable) peaks and valleys in populations of prey
Peaks and valleys are caused by diseases and famines, wolves are the worst enemy for livestock and wild deer diseases, so the final result is deer populations more stable and health in fact.
People, specially children, would be also much more safe with wolves than without them, because... first of all, less car accidents with deer, second: less americans killed or having pain by Lyme disease, Rocky Mountain spotted fever, Tularemia, Ehrlichiosis, Relapsing fever, Colorado tick fever or Babesiosis. All tickborne diseases, spread by deer or small carnivores, that are a much bigger threat for children playing outdoors because ticks are everywhere in deerland.
> Apex predator birth rate is low and it would take years to have a noticeable effect
Not necessarily, because the "ecology of fear" change the behaviour of preys. You don't need to wipe out all deer at all. In Yellowstone wolves changed all for better in just five or six years if I'm not wrong.