I think people get confidence differently with cartridges.
I shoot quite a bit, I'm a bullet nerd and I've got to shoot quite a few critters with quite a few different cartridges. The more I shot and the more I got to autopsy the more I realized from a damage standpoint when they're hit in a similar spot I couldn't tell any difference between any non mag cartridge. I've only ever killed 1 coyote with a magnum, I've shot them up through a .458 win but rare was the day one went to the woods.
Other guys get confidence from horsepower, a whole bunch of them hope that it will make up for poor shooting.
A real good friend of mine shoots 2-3 shots a year, zero practice. He listens to guys that say a bunch but they just don't know a lot about guns. He got a 243 last year and bought a box of 95gr fusions. He asked and I said shoot them like you would anything else, hug the shoulder.
The guys told him absolutely not, a 243 can not break a deers shoulder.
So, the day comes and an 8pt steps out, he shoots, it runs. We track and find it about 200yds away. He knew he hit it right behind the shoulder and the bullet just didn't penetrate. He declared the 243 had no "knockdown power"
His shot was deep on the ribs, so liver and guts. He could have swore he hit it in the shoulder but he obviously didn't. He refuses to use that rifle again because he has no confidence. I also can't convince him that poor shooting is poor shooting.