They make perfect pop songs, they are smart. They know what is going to sell. Things that everyone is gonna sing along to involuntarily. And they have star quality that people are just drawn to. Their songs are relateable and very radio friendly.
They make microwave pop music especially tailored for radio. They don't take risks and radio loves that. I mean Gaga took loads of risks with BTW and her singles did well but didn't go number one. So radio microwave hits are whats in but now the industry is moving more towards male, indie band dominance and Bruno will be the only one who will survive it.