If one has a real hankering to use a single shot, for example some historical or vintage rifle, that makes some sense. And if one is practiced in reloading quickly.

But if hunting, and taking a shot at a great sable, eland, kudu or whatever, and a quick second shot is needed and the animal is lost as a result, or a day or two of tracking is needed to find it again, then a bolt action is better. Or of course a double rifle within range, with the first barrel, and follow up shot with the second barrel.

With a double I learned to not take risky shots with the second barrel having already fired the first barrel at another beast. Same as a single shot with every shot.

A good classic vintage single does have a lot of class, and imposes a lot of discipline on their users.