He's a survivor of a mob war, his inner circle is very close to him (as you said, nobody flipped), he seems to be tight with the most important NY families (who backed him since he was a young hood) and he has good relations with many other criminal networks in Philly. He has been running the family for more than 20 years now.

Whether he's smart or lucky...one can safely say that he's good at the job of being a mobster.