A band is a combined effort of all the members. They each did there own part to make it a success.
Yes it's the 'sum of all parts > than any one individual' that make up any band. Balancing egos in any group larger than 1,,,
,,,is as difficult as writing songs performing live shows.
However in many instances one member can be the glue that holds the band together, like in Zeppelin's case it was John Bonham. (There are some LZ experts in here who can correct me if I'm wrong but I think that was the main reason LZ went their separate ways.)