In my experience, very, but it’s also not magic. Being able to package an application with its environment and ship it to any machine that can run Docker is great but it doesn’t solve the fact that modern deployment architecture can become extremely complicated, and Docker adds another component that needs configuration and debugging to an already complicated stack.
Boeing can’t really replace workers. The union is so strong because aerospace machining is a very difficult job that takes years and years to learn—if they cut their workforce and start anew, they will lose enough productivity that it won’t be worth whatever wages they save.