Surely a 'medium' is an intermediary that is used to create something else. The Oxford Dictionaries definition supports that view:
So if photography is a medium it is not a set of outcomes (such as a 'documentary') but a means of achieving those outcomes. So one might have a documentary drawing, or essay or indeed photograph. It is an interesting conjecture whether an advertising image is a 'documentary' - I would say it is naive to expect advertising to document the product being sold in a neutral way.
Doesn't matter if the reason is justified, it still happened - average folks don't trust photography anymore, and the reason is manipulation of image content.
Some may not be aware enough to think it through, but most would realise that it's the manipulators of the medium that are not to be trusted. Who would be participating on photography sites if they didn't trust them?
I think the root of the problem is our false assumption that there is an absolute truth in a photograph, or our desire to apply an absolute label to one. The camera has always isolated, distorted and abstracted it's subject. And we as viewers have always extracted meaning and labeled according to our own understanding/memory/experience even to the extent seeing only those meanings that fit with our own bias/prejudice sometimes with barely a glance.
It's the belief that a photo is a representation of truth that is false. It contradicts the nature of a photo and the human nature of the viewer. Now it's so easy that anybody can do it it becomes obvious that there is little absolute truth in a photo. We need to recognise the truth not perpetuate the illusion.
“If you start cutting or cropping a good photograph, it means death to the geometrically correct interplay of proportions. Besides, it very rarely happens that a photograph which was feebly composed can be saved by reconstruction of its composition under the darkroom’s enlarger; the integrity of vision is no longer there.” A quote from Henri Cartier-Bresson. When I was kicking around in Art school to save my sanity from writing my PhD dissertation in mathematics, one of my art school professors had two students who where disciples of Cartier-Bresson. Both were amazing photographers. All of their prints showed a black irregular frame around the image. It was from taking a file and filing out the 35 mm film carrier so that they could prove they did not crop. That is the same thing HCB had done to the film carriers in his lab where hired technicians printed his images. HCB didn't print.
On the other end, W. Eugene Smith famously said, the "word does not often contently fit in a 2x3 frame." In fact W. Eugene Smith never saw a darkroom manipulation he didn't like which let him to getting fired by Life at the time. Today even Time-Life has changed its tune a bit.
I think today the distrust in images and photographers is well earned. On one hand cropping to make modify the aspect ratio of a print is much different that using AI sky replacement.
For me creating a depiction is a sine quo non of photography. One thing can have many truths – indeed, there as many truths as there are witnesses. You can no more trust a camera and lens to be "truthful" than you can trust your own brain and eyes to be because both are subject to your biases.
Definitely macro or wildlife photography -- you gotta lie on your stomach to get the shot sometimes! Well, technically, maybe it's diving photography, since they can go pretty deep. Selfies are usually taken a few feet above ground, so they're out of the running. 😁