Is OpenAI's use of copyrighted material legal? Should it be?

Recently, several prominent authors have sued OpenAI for infringing on their copyrights. I have sympathy for the authors in this matter. But any defense of OpenAI would note that by using the authors' writings, among its input, OpenAI has made new services available to us all. It has become a platform that could make both our lives and the business world more efficient. In your opinion ... Do you think its use of copyrighted material is legal? Should it be?