Without doubt early science was well served by Islam, however this was not without some degree of assistance form others. The ancient Greeks and Egyptians not to mention the Chinese had all contributed to science in various fields... Long before any "religion" had arrived. Also the early Christians and Jews were well skilled as literary scribes... So I see early science as a combined effort of mankind's collective intelligent endeavours.

You could ask why does Islam today not lead the world in this way... Why did it all stagnate? Maybe much like the pagan societies of the ancient world.. Greece and Egypt et al.. All good things come to an end and we all have a turn to shine at something at some point.

:)

peace