Bear spray will work on a bear that is well fed and not diseased.I would never rely on it to defend my life from a bear.
But if a bear is really hungry, or has rabies, bear spray will not stop such a bear.It will follow its prime directive to feed. And to a hungry bear a liitle bear spray is hardly as bad as being stung by an entire nest of bees when getting wild honey.As a matter of fact , bear spray can get a bear very, very agitated.
The best thing you can do when confronted by a bear is to leave, or alternatively have a heavy caliber firearm in case the bear charges, which can happen , very, very fast. In the blink of an eye.
You want a bear story? Read that of Freeper Kanawa.He stabbed a black bear to death that has seized his dog in its jaws. (Kanawa do you have the link to that bear story, I can’t find it after searching.)
The fine motor control that humans have in their arms and hands comes with a price tag of less strength and less speed.
Bears also bite an adversary's head. One of my City Commissioners was attacked at sunset by a female bear with cubs just a couple hundred feet from his Cascades weekend home.
The guy survived, but he looked like a zombie until a half dozen plastic surgeries finally put his skull and face back together.
When you’re really hungry, pepper spray is as good a seasoning as any other.