Pablo Picasso was one of the most famous modern artists of the 20th century. While many of his paintings border on the abstract, he sharpened his artisitc skill on more realistic and traditional styles. Novelty and creativity are important parts of great art, but just as necessary to making anything great is the technical ability to take an idea and represent it in the real world — even abstract expressionists could paint unbelieveably realistic landscapes if they felt the need.
I’m certainly no artist, but the lesson here applies more broadly: practicing technical skills on their own is an important part of the creative process.