Agreed. If not, you could just as well have said "If a colleague can do your job, you're not needed."

It's actually an interesting point that. Oversimplified a bit, I feel there are two different ways that people measure their worth in the workplace. There is "no one else can do what I do" and then there's "I make sure that everything I do can be done by someone else".

Personally I much prefer the latter.