The issue for me, not being an art aficionado, is that it is abstract and therefor becomes subjective; a matter of opinion. I guess that if you are able find two or more people who agree, then that an abstract artist can be “great.”
I prefer a realist like Davinci and Rembrandt. I especially like Davinci because he was more than just an artist but a scientist and engineer. Maybe an Einstein of his time.
I don’t know if Leonardo or Rembrandt were realists - I’m not sure the term was ever known in their lifetime. What you mean is that you can see immediately what they are portraying. That is sometimes labelled as naturalism although that term wouldn’t be known by them either. This is what people hated about the impressionists - you couldn’t always tell what they were representing. Today, of course, people who know nothing about art can appreciate them. Their eye has become used to seeing.