Shouldn’t UX be Lean and Agile inherently?

People describe different types of UX such as Agile UX and Lean UX. Looking at the Agile manifesto and Lean methodology, it would seem to me that a successful implementation of UX processes would require a flexible and efficient process anyway.

Is the use of Agile or Lean UX redundant or does it mean something more that I am not aware of?