Because, abstract art allows artists to express emotions and ideas freely using shapes, colors, and forms. It gives each viewer a unique experience, allowing them to interpret the art personally and connect them emotionally, without the need for realistic details.
I make representational paintings. Over the years I've made a handful of abstracts. I've not been that pleased with the results but others seem to like them. Which makes me like them even less. I always get the feeling I'm wasting materials, and I don't feel the sense of accomplishment that I get when I make a good representational piece.
HOWEVER I find abstracts much easier to live with in the home. After a short while, even the best paintings become "invisible". You forget they're there. Good abstracts have a much longer "wall life" and become an integral part of the living space in a way representational pieces often do not.
I can appreciate the skill and craftmanship in a representational piece even if i don't care for the subject matter or style. But I have a very particular/opinionated taste when it comes to abstracts. I either like it, or i don't.