People use photo-mode for the same reason they use cameras in real life. They see something they like, something that fascinated them, something they think is interesting, their point of view.
There is also something deeper in it. We live in a real beautiful world, but we don't always have the opportunity to explore it freely. Meanwhile, someone creates a beautiful virtual city filled with interesting places and we can visit and photograph them. In the world of CP2077, people are taking brain-dance screenshots in places that no longer exist, forests, destroyed Dubai, etc. We sit at home during a pandemic and brain-dancing in Night City taking screenshots of what we see.
There is also something deeper in it. We live in a real beautiful world, but we don't always have the opportunity to explore it freely. Meanwhile, someone creates a beautiful virtual city filled with interesting places and we can visit and photograph them. In the world of CP2077, people are taking brain-dance screenshots in places that no longer exist, forests, destroyed Dubai, etc. We sit at home during a pandemic and brain-dancing in Night City taking screenshots of what we see.