A lot of what sous vide does well, you can do with other methods. However, sous vide adds a ton of convenience and repeatability, making it great for entertaining. We made steaks for tailgating that way. Cooked them sous vide the night before. Took them out of the cooler during the tailgate and sear them up on a ripping hot grill. Done to a perfect medium rare after a minute or two per side.

Aside from the convenience and precision, it does have an application unique to sous vide. It can cook tough cuts normally reserved for braises and cook them to a much lower temperature. You can cook beef short rib to medium rare and have it be just as tender as a fillet. Of course it will take you ~3 days.