What is the purpose of a telescope gathering a much wider cone of light than the human eye?

Answer

Making the object appear brighter and allowing for higher magnification.

A large objective gathers a wider cone of faint light and concentrates it, which makes the object appear brighter and consequently allows for higher magnification without the image dissolving into darkness.

What is the purpose of a telescope gathering a much wider cone of light than the human eye?
Definitionastronomytelescopeinstrumentoptics