Illustrator can be a profession on its own. There are many talented artists who replaced pencils  with digital tools and became illustrators. Each Illustrator strives to develop a unique style. Illustrations have always been very enjoyable projects for me. Unfortunately, there hasn’t been a frequent demand for them. As far as the style goes, it is always a subject to topic and nature of the project, same as the trend for any design. In some cases, this decision is made intuitively in other cases it is intentional rational choice.