Well the one colombo guy that tried to end carmines reign, orena, started a war that got a decent amount of people killed and a lot more guys put in prison. So after that carmines position as boss was cemented again. Nowadays everyone in the family knows that another war would completly destroy the family.

"Let me tell you something. There's no nobility in poverty. I've been a poor man, and I've been a rich man. And I choose rich every fucking time."

-Jordan Belfort