As a mountaineer's point of view ...
All 7 peaks are in different ranges making them renowned in entire world by alluring all the climbers towards it. Though every peak has its own level of difficulties and distinguish climatic condition which also make them unique.. significant for tourism
As geographical's point of view
As I mentioned about all peaks are in different Ranges so these ranges help in many ways.
like - Obstruct the destructive wind flow, helps to balance oceanic currents,safeguard mankind and wildlife etc..
7 Summits as follows:
Mt. Aconcagua (S.america)
puncak jaya (Australia)