Klaus Wunderlich“ Wersi sound, which you probably won‘t find quite like this in the factory soundset...
You can certainly edit factory sounds also
to suit your needs Pa4x is a powerful tool.
Yes you can...
But some people prefer to buy finished high quallity sounds
Why do you think Yamaha sells so many expansion sounds?
Not everyone cares to make his own sounds
Its just like with styles
Some people make their own styles
Others edit their styles to their needs
While many just buy or trade styles with others.
Why else would Korg offer 3GB of sample ram?
As to allow people to buy new sounds?