For me, the only time that applies is when I shoot reversal/slides.
Even then, using mylar tape, I can crop the slide.
For negative film, invariably, I will want to do something different in the darkroom than what I had in mind when I shot the image. As was mentioned, many times I see other images inside the image that was taken, and to get those, I have to crop.
When I shoot certain types of photos, like action sports or active kids, I do NOT have time to do final cropping in the camera. I have to shoot to the best of my ability to just get the shot. Then do the cropping in the darkroom. Have you ever tried to follow a small kid around the house at a birthday party, or even shooting an 'in place' portrait. Small kids do NOT STAY STILL.
Something I learned the hard way, I need to give MORE space around the subject to be able to crop to a desired paper size. The problem is the HxW ratio of an 8x10 or 11x14 paper vs. a 24x36mm size of a 35mm or a 6x6 film image. Wanting to make an 8x10 print with ALL the image from a 6x6 negative, I will have an 8x8 image with a 1 inch white border on both ends of the long axis. IOW, moving in too tight with the camera, limits your ability to make prints in the darkroom. How many times have you wanted to print the entire long axis of a 35mm negative on 8x10 paper, using the entire paper, because it has to go into a commercial 8x10 frame? Ooops, the image is not wide enough for the paper, drat. What if the client wants both a 5x7 and an 8x10? The HxW ratios are not the same, you have to crop to fit.
As for selecting the camera format, I do not see that as a realistic option. I will take whatever camera I decide to use, whatever the reason. In the field, when I run into a different "format" scene of a different HxW ratio to my camera, I will not go home to get my other camera. I use what I have with me, and plan to make the desired image in the darkroom, by cropping. I am NOT going to carry ALL my cameras with me, as that is a dumb solution to the perceived problem, and I do not have 2 porters and a van to carry ALL my cameras and related gear. And as I get older, I am shifting to lighter gear, with the associated compromise of format and lenses.
I have also shot MANY square compositions with non-square format cameras. I have sometimes run into situations where I could not figure out how to shoot the shot so it was NOT a square. In fact, why force a square image to be a non-square? If the best composition is a square, shoot it as a square. I am also not going to switch cameras from a 35mm to a 6x6 during a shoot just because ONE image is a square format. I will shoot the image with a non-square 35mm camera and crop to a square in the darkroom.
As has been mentioned, image level. I use a P screen in my Nikon, to help with keeping the image level; a horizontal horizon, vertical buildings, etc. But I still end up with images that are NOT level, and for some reason that I do not understand, it has gotten significantly worse as I get older. So I have to leave extra room to crop to level the image in the darkroom. Rather frustrating.
Finally, there is the situation of a book/newspaper/magazine. The editor may give you a desired print size to fit into a spot on the layout, which may have no relation to the image on the negative, and you as the photographer, have to make the best effort to print the negative to the desired size. Example, make a 3x3 print of a flag pole. There is going to be a LOT of excess image on the sides of that flag pole to make that a square, and you NEED that space to accommodate the unpredictablity of the editors. I have had to go back to the editor many times and "try" to tell them I simply cannot make a print of that image ratio, as the image on the negative will not support it. Always with a print with grease pencil lines of the specified print ratio to show them. Yes I was caught short MANY times, and had to force fit an image into a desired print size, and the resulting print was NOT something that I was happy with. So I had learned to leave a LOT of extra space around the primary image, to accommodate the unpredictable size requests of the editors. If you are not in this environment, consider yourselves lucky.
Having said all this, I remember one clear reason for shooting tight, was grain. The larger you printed, the more visible the grain was. So to minimize the grain, where we knew the final image was going to be large, we tried to shoot tight with fine grain film. But sometimes it was after the fact and it was a miss; someone wants a 16x20 print of a cropped 35mm image shot with Tri-X and pushed. OUCH.
So one may have a goal or philosophy, but the real world sometimes gets in the way, and you have to accommodate it.
I call it making the best of a situation.