One of the better discussions of the various national parks I have checked:
https://www.nps.gov/grsm/learn/nature/black-bears.htm
I have spent many days in that park, with an estimated 1,900 black bears, and I have only seen two bears on the trail and heard a third that jumped down a steep slope to get away from us. The two I saw, one at maybe thirty yards and the other at half that, slowly ambled off. I have never had a bear raid my camp at night.
This is not to say there are never any problems with bears. There are currently four backcountry sites closed due to aggressive bears, and another six with warnings. All sites have hanging cables.
Additionally I am aware of seven predatory bear attacks in the history of the park (the earliest in 1986 or so), where the bear was after the people, not their food. Two were fatal, and in both cases the hiker was alone. In the other cases, most if not all with significant injuries, there were other people present who assisted with beating/chasing the bear away.
When I backpack in SEKI I use a canister. My brother has chased bears out of camp there.
A black bear with ears up, swatting the ground, bouncing as it charges, wants space. A bear with head and ears lowered, approaching deliberately, means business. Fortunately I have never dealt with either behavior. Despite this I have started carrying bear spray in the Smokies.

