Yeah that does confuse me as well about the guy who doesn’t know about using external flashes. I for one have only minimal experience using studio flash and lighting (from when I worked for a photographer who had a studio) but since I do not have a studio of my own yet, I do not use that equipment. I use hot-shoe mounted flashes when necessary but most of my work is natural light.
Technically, the black-and-white that you can take in the camera is sort of “processing” because it just does an automatic version of monotone. It’s typically very flat. I’ve tried it before on my DSLR but much prefer to shoot in RAW (in color) and then process as black and white later, while adjusting the contrast etc.
In many ways, at least in a business sense, it’s a requirement to do some editing. For one, you should always be shooting in RAW. Even if you do only minimal editing, you then export it as a jpg. Everything will look better when the image is shot right in camera, which will minimize editing. When an image is bad from the start, you can tell it’s been over-edited. The way technology is today, a photographer who doesn’t do any editing is going to have less appeal than one who does their editing well. That’s the artistic side to it. You just have to keep up with the current technology in order to draw clients and keep clients. Film was “edited” in the darkroom with dodging, burning, filters, and sometimes using different chemicals. That’s the technology that was available then, but we are not limited to that now. Obviously, those who knew their equipment and the other technology that went along with it, both then and now, were and are more successful.