Of course, he doesn't sing "super." His voice is rather interchangeable and doesn't have the quality of other well-known singers like Sheeran, Mercury, Mendes, Presley, etc. But for venues like the Stadthalle Heilbronn or the Rathausplatz in Kassel, it's sufficient. And as for the song lyrics, which could almost be from a furniture-living-catalog ("Living like a firework, firework... oh oh..."), I don't even want to get started. But at least it's suitable for suburban moms and similar audiences. It'll certainly generate enough revenue. ;-)
But what I really appreciate about him is his excellent and patient interaction with his fans and his always positive attitude. And of course, I don't need to mention that he looks damn good and trains hard for it.