Having done professional design work, photography, video editing, 3D animation, yada, yada, yada: I can’t think of a time where I’ve been unable to achieve my color goals in still photography with PS’s or Lightroom’s tools. For people to bother learning new professional tools, there needs to be a more concrete reason than ’but this is one is technically better.’ For hobbyists that are really into the tech? Sure. For professionals that need real precision and consistency— e.g product photographers shooting a lot of stuff with precisely defined brand colors, wedding photographers whose photos will frequently be looked at in series, or something? Sure. For most, the ROI on the time spent just isn’t there. The use case for more precise and consistent color grading in movies or other professional video is obvious— when all the frames are there sitting next to each other, and subtle color changes can so drastically affect the mood of the piece on a while because it’s so immersive. But most professional images are seen in specific contexts with other elements, often through unpredictable media… those tools just aren’t as useful there. And they’re also more complicated — simplicity is a huge boon for efficiency, and efficiency is really important for professional work.