That said, you can line up Who By Numbers with Presence, and Who Are You with In Through The Out Door as later albums by the top bands of the 1970s that were ok, and at times stellar (Achilles Last Stand is Zeppelin's best IMHO) but not quite as good as a comprehensive work as prior efforts.
And they should all be denied healthcare, those aging wankers.
"Music Must Change" is another great song.