This is very common because of the way transport is built and sold. Doing real traffic engineering where shared risk link groups do not exist for the active an

This is very common because of the way transport is built and sold. Doing real traffic engineering where shared risk link groups do not exist for the active and standby links is a lot of work and, moreover, is hard to keep working as operators change their networks (for maintenance, for other reasons). On top of the basic difficulty, there are other issues - layering makes this opaque, the service providers have become completely de-skilled, the business model for MPLS is getting killed by Over-The-Top providers who pretend they can give you equivalent service using multiple links and IPSEC tunnels. And so on.