Why is collaboration of scientists progress of science?

Answer 1

All knowledge builds off of other knowledge. We build off of things we know to grow knowledge further, rather then having every person discover everything again for themselves.

This concept is often simplified by the famous quote about standing "...on the shoulders of giants, so that we can see more than they, and things at a greater distance...". -Bernard of Chartres

In this way, we take in the knowledge of the past, and improve it. Each generation does not have to invent the wheel in order to build the wagon, we don't have to invent the wagon to invent the cart, and we don't have to invent the cart to invent an automobile.

Modern science is in the same way reliant on the knowledge of other scientists. When knowledge is horded, that knowledge must be re-acquired by others just as wise as those who first discovered it, which takes away time they could have spent moving knowledge further.

This is a simplification of the core issue, though the addition of large financial investments and legal issues complicates it greatly.