There is always the "Beware the hunter with only one gun, he probably knows how to use it." argument. Some say use your big gun on everything so when the time comes and the chips are down in a life or death situation, everything is second nature. Full bore 458 Lott rounds can detach retinas though, if shot in long sessions, so you do have to be careful.
I read what an African PH wrote who only owned and used 3 rifles, 3 Win. Mod 70's, tricked out with finish, stocks, bedding, barrel lengths etc. all matching. The calibers were 30-06, 375 H&H, and 458 Lott. With all 3 rifles having nearly identical stock geometries, trigger pulls, safety mechanisms, etc. it was almost like shooting the same rifle with different loads. The biggest difference being the difference between the stand action and the magnum actions. The 30-06 loads and 375 H&H loads were chosen for nearly identical trajectories at normal hunting ranges, and of course the 458 Lott was usually a 100 yards or closer option, so trajectory was not an issue. He used the 30-06 hunting everything except large-bodied game. He used the 375 H&H hunting large-bodied game and speed training at the range with the long magnum action. He used the 458 Lott ONLY on dangerous game. He shot regularly enough with the 30-06 and 375 H&H to keep shooting skills sharp. He only fired the 458 Lott 10 times per year in the off season right before the start of season over 2 or 3 range trips. 2-5 shots per range trip for a total of 10 shots, just to make sure everything was functioning properly. The only other time he fired the 458 Lott was on the job usually at dangerous game.
That sounds like a very prudent approach to me for several reasons, on several levels, for a person who could be called on to save lives in an instant, with a rifle, reacting entirely on muscle memory and autonomic nervous system response (which is what every human does in a life-threatening situation with no warning.)
Personally, I have hunted exclusively for decades with a 30-06 and 180gr loads for everything from 40 pound javelina to bull elk approaching 1000 pounds. The largest dangerous game I could encounter is a 300 pound black bear or a 100 pound mountain lion. These animals are lethal to be sure, but rarely encountered. I have never felt the need for more gun.