Mr. Brian wrote:"Echo & The Bunnymen" as a band has not written a song since 1997. Evergreen lists "All tracks written by Echo & the Bunnymen" that was the last time. It's been just Mac or Mac/Will ever since. Mac gave Will some credit on Flowers and Siberia but that's about it.
Both Flowers and Siberia credit all songs to both Mac and Will. Of course that does not mean they came with them as a tandem, but they agreed in sharing credits for a reason (i.e. enough input by Will). That hasn't been the case the last two albums.