It turns out, you don't need thousands of ft/lbs of energy to be effective.
Pistols are simply handier, and on you when they are needed, instead of leaning against a tree, or slung over the shoulder.
Over a hundred cases of pistol defenses against bears - they are 97% effective. Caliber is simply not that important, for a number of reasons.
Here is a recent case: Bear shot three times from 460 yards, with a .338 magnum. One shot to neck, hit nothing vital. One shot to chest, only holed one lung. One shot to shoulder, did not break shoulder.
Rifle then jammed in such a way the shooter could not clear it quickly. Large Grizzly boar charged the hunter and his sister (from 460 yds!). They retreated, got out of the way. The bear followed them until the hunter shot it and stopped it with his revolver, a Taurus 5 shot in .454 Casull, as I recall.
I understand but look at the way this story starts. Shooting at a bear at 460 yards is stretching any rifle let alone a 338 and it seems the results were rather predictable, wounded bear. Now given a choice between shooting an aggressive bear at let’s say 25 yards with a 454 Casull or a 300 Win mag which would you choose? We’re talking rock chunking distance not 460 yards where the round has already lost close to a third of it’s energy and starting to drop fast. Hey if a person wants to carry a pistol that’s fine but like I said in my first post carry enough and in my opinion the 10mm isn’t enough even for black bear, I’d start with a 44 mag or 45 LC and go from there.