Airbus's suppliers already have a hard time keeping up with airbus right now. Why would they add a concurrent that depends on the exact same supply chain, when

Airbus's suppliers already have a hard time keeping up with airbus right now. Why would they add a concurrent that depends on the exact same supply chain, when they have taken delivery engagements for the next decade. Unless the price is truly astronomical ,but then it's not worth it for Boeing anyway. And that's before touching reputational damage that come from building your concurrent's plane because you couldn't design your own.