One difference is that the photographer has to go the places they're taking pictures of.

Another is that photography isn't comparable to paintings and it never has been. I'm willing to bet photography and paintings have never coexisted in a contest. Except, when people say their generative art is comparable to what artists have been producing by hand, they are admitting that generative art has more in common with photography than it does with hand-crafted art but they want the prestige and recognition those artists get for their work.