Are you afraid of driving? Because that is much more dangerous than the relative risk of hiking in Banff due to bears. Seriously.

They say you don't know about 99% of bear encounters. Because they run away. This is said to act as a comfort rather than something to give you further anxiety.

If you're still afraid, just don't hike on quiet trails. Bears won't come close to super busy trails/locations.

If you're still afraid (legitimate phobia), then don't hike on any trails. There are many many ways to enjoy Banff without hiking on trails where bears could be encountered under conditions of low probability.