It’s hard for most people (including me) to look at a scene in color (the way our eyes see it) and imagine that scene in black-and-white.
Plus, with a DSLR, you have the added benefit of seeing the image in black-and-white immediately after shooting. It’s hard for most people (including me) to look at a scene in color (the way our eyes see it) and imagine that scene in black-and-white. So that feedback is important. Better yet, if you’re using a mirrorless camera, then you can see the scene in B&W, in the viewfinder, before you take the picture.