An architect doesn't go off with a shovel and dig his foundation and lay every brick. He's still an artist.
Ideas alone can be works of art; they are in a chain of development that may eventually find some form. All ideas need not be made physical.
The idea becomes a machine that makes the art.
Minimal art went nowhere.
Minimalism wasn't a real idea - it ended before it started.
All intervening steps, scribbles, sketches, drawings, failed work models, studies thoughts, conversations, are of interest. Those that show the thought process of the artist are sometimes more interesting than the final product