If you don’t care about color, then it doesn’t matter. If you do care, as most professionals should, it matters greatly. RGB and CMYK have extremely different

If you don’t care about color, then it doesn’t matter. If you do care, as most professionals should, it matters greatly. RGB and CMYK have extremely different gamuts of reproduction, not even counting what your output medium is capable of rendering (whether that’s your display range or your ink+surface range)