Why would I buy when I can generate my own? lol
I guess your argument could be changed slightly to "Why buy stock photos when I can take a photo with my phone?"
it's pretty easy to tell some generative software to "Female giving a presentation in a well lit office with windows open" and get something pretty decent.
This goes for anything that needs props that a normal person doesn't have.
Is it? I tried that exact prompt with dall-e and got 4 images with nightmare fuel faces: https://imgur.com/a/yyt5Tax
Tell me you haven't tried Stable Diffusion without telling me you haven't tried Stable Diffusion.
I agree that anatomy and hands are a problem. Give it 6-12 months and they won't be. That's how fast things are moving at the moment!
As someone who actually tried it, with current models it's possible but neither easy nor straightforward. Getting decent and coherent images is still hard and requires finetuning, so there is certain value in this. And for very specific and series-consistent images I'd still rather set up a photo session if I had a studio.
It will change for stock photos, but probably not very soon.
"female with two hands that have five fingers, and normal looking face, giving a presentation in a well-lit office with correct shadows, and a clock on a wall that is perfectly round with legible roman numerals correctly placed around the dial ..."
Honestly not a lot though, it's so easy. It's not really comparable to taking them with a phone because you don't have to have access to the subject!
Or possibly you would have to have your own model which is trained on that space of images that is relevant to what you are looking for.
Look at what virtually all the hobbyists and enthusiasts out there are doing with this stuff. It's almost all exlusively these: surrealism, fantasy and dumb memes. In all these fun genres, bad details, like hands with six fingers, or laughably wrong shadows, do not matter.