Vector graphics is a medium like any other medium in digital or traditional art. It has its followers like any other medium, and is based on the preference of the artist. It is not a defining way of creating ‘e-art’ - there are others (pixel art, 3d graphics) - but it is another way of creating art.
There are many different softwares available to create vector art (graphics). Adobe has a proprietary software called Illustrator. There are definitely other options available.
I use Inkscape - an open source vector graphics software - to create my works. These different softwares are just tools of a digital artist like paints, oils, brushes and canvas in the hands of traditional artists. The choice of a particular software lies in the preference of the artist.