Soft Components follow the neumorphism design concept which plays with the light and shadow of the "surface" of the user interface. This design language is pleasing to look at and provides the feel of simplicity and elegance if it is applied appropriately.
The neumorphic design has its limitations and should not be applied everywhere. Hence the Soft components is a set of decorative components that hopefully will help your site stand out from the crowd.
The theme store (coming soon) will hopefully give you an idea on how these components work together with other design methodologies such as Material design and minimalist designs.