actually there is guys who effectively use tree stands for bears. Bears can be really easy to pattern do to there need to feed in the spring. I have not used a tree stand personally but have successfully ambushed them on the ground
Tree stand can be effective for any species you succeed to pattern and the location provides a tree. I know of all species of deer taken this way, moose, elk, black bear, grizz, and even a bighorn from Canmore bow zone.
No doubt it is more effective for some species but if you have a reliable location to ambush any species it can work
Great tool when used correctly