I'm looking for a better looking and feel development..
Swing offers 4 PLAFs as standard. There are at least a dozen more 3rd party PLAFs, some with dozens of variants. Of that plethora of possibilities, end-users generally prefer the 'native' PLAF - which looks and feels mostly like 'every other native app.' on their machine.
You can see a small app. that changes PLAF. on the Nested Layout Example. Here is the Mac. native PLAF.

..why do you think it is not easy?
This was said in relation to a general comment that it is harder to build a GUI in Swing than (for example) Visual Studio.
The reason for that is that Swing is intended to work on multiple platforms, screen-resolutions/sizes, PLAFs (and other factors). As such, 'dragging and dropping' components into their final position is impractical, since that might change according to the factors listed above. Instead Java relies on the concept of layout managers, which calculate the size and position of components as they appear at run-time.
The layout managers use 'logical groupings' of components to achieve the desired general shape expected of a GUI. The image above is an example of how to combine layouts to achieve different effects in different parts of the GUI.
Although I don't use GUI builders for Java I do feel that they can increase productivity, it is just a matter of:
- Already knowing what Java Layouts are available, and how to use them.
- Using the standard layouts in combination in the GUI, to achieve the desired effect.