Same end goal, two very different starting points
Photography starts with a real, physical object in front of a camera. Rendering starts with a 3D model and builds the lighting, materials, and camera entirely inside software. Both can end up looking equally real — the difference is in what's possible before that final image exists.
Where rendering wins
A product that doesn't physically exist yet (still in prototyping, or only exists as a CAD file), a product that needs to be shown in colorways or configurations that haven't been manufactured, or a scene that would be impractical or expensive to build physically — rendering can produce all of these without a physical sample.
Where photography wins
Real material texture that's hard to fully simulate — fabric weave, worn leather, condensation on glass — photography captures it for free because it's actually there. It also tends to be faster and cheaper for a product that already physically exists in front of you and just needs a clean, well-lit shot.
The honest deciding question
Ask whether the product exists yet and whether the exact scene is realistic to build physically. If both are yes, photography is usually the faster and more cost-effective path; if either is no, rendering is often the only realistic option.