Do they expect to gain something from this distribution?
Interesting question.
I think that the answer is that by providing their userbase with tools to better manage their graphics card / display they will maintain user loyalty to
their display adapters as opposed to their competitors.
Further, there are possibly features of the graphics card that are not accessible (or not easily accessible) through the generic Windows interface, and their control centre software facilitates access to these features.
Conversely, if their competitors provide similar, they have to do so to ensure they don't fall behind in the arms race.
It is also possible that the control centre software reduces support costs for themselves by making it easier / more obvious to configure, maintain and update graphics card functionality and drivers.
Of course they may just be using it to spy on you!
SD