All photos have always had post processing. In the past, we would shoot a shot and have prints made. Those prints were post processed. They were cropped in many cases by the printing process. They were color corrected by the printing process. And so forth. If we did our own processing, then often we pulled or pushed the development of the negatives, then we dodged and burned in printing (and almost always had to crop if printing 8x10 for example from a 3x2 format negative).
Nothing much has changed. The photos that come directly out of a digital camera almost always need a little contrast punch and sharpening.
Often the 3x2 ratio of the average digital format is not what is desired for optimal composition and so cropping occurs to change that ratio.
The question is whether the post processing makes the photo better. If it does, then it should be used.
Overall, it is still very desirable to do as much in the camera as one can. The more done there, then the more data that is available to be spent in other manipulations of the photo.
Regarding your three example photos: They are all reasonable photos from the camera, but each could do with a little improvement and some of these improvements can be done in post. #2 and #3, for example, would be better with some cropping. #1 seems to have no detail in the blacks of the dress and probably in post this could be corrected. #2 will be hard to correct since the in camera cropping is not going to allow much in the way of more favorable cropping.
If we shoot RAW, then we always post process. So I think post processing is a part of our photographic adventure.
My overall take on how I make a photograph is this: I see a scene in my minds eye. It combines model, background, lighting etc. Rarely does that vision in my mind equal what I can create by manipulating of the scene and its components. I can get close sometimes, but often not, and the amount of work to get close, may be excessive. So I think about my vision and the reality and with a knowledge of what I can do later in Photoshop, I make the final in camera shot (and know in advance what PS work I plan). I learned this concept or approach from Ansel Adams. Every shot he made was manipulated in Post (file development and darkroom) and pretty much followed the idea that I have just presented.
Hope this all makes sense.
Re: Just how much?