As per Wikipedia:

As of 1 January 2017, Mauritian citizens had visa-free or visa on arrival access to 131 countries and territories, ranking the Mauritian passport 33rd in terms of travel freedom according to the Henley visa restrictions index.[1] As of December 2017, Grenada, Serbia, Seychelles and Mauritius are the only countries whose citizens may travel without a visa to China, Russia and the Schengen Area.

Mauritius does not have the bargaining power of European Union, nor is it a superpower, nor does it play important role in global politics, what gives it the edge? I know about reciprocity of visa, but it needs some bargaining power.