Are Lisp programs inherently hard to maintain? If macros allow a Lisp program to become its own programming language, does coming on as a new maintainer have a

Are Lisp programs inherently hard to maintain? If macros allow a Lisp program to become its own programming language, does coming on as a new maintainer have a much steeper learning curve than for programs written without macros? What about after that learning curve is surmounted, does it become easy to maintain after that?