Where it really has value is if what you work on is like 33% extremely difficult and 66% boilerplate/tedious. Being able to offload the tedious bits can make more senior engineers 2-3x more productive without the coordination effort of "find a junior engineer to do this, schedule their time, assign the work, follow up on it".

(The problem of course is you still need these junior engineers to exist in order to have the next generatino of senior engineers, so we must now also think about what our junior folks should be doing to be valuable AND learn).