Before the advent of photography, in painting schools realism was the way to go, people studied the past masters and tried to paint as realistically as possible, especially portraits. Then photography came along and painters realized that realism was better left to photography... Artists realized times had changed so they needed to paint in new ways... That reaction led to impressionism and expressionism and cubism etc. etc.. Painters left realism to photography and moved on.
B&W film was the medium of choice because color film compared to it was terrible in every sense of the word. Today that is no longer the case... So the same way that realistic paintings of the past are admired but no serious artist paints them anymore, the same way while the B&W legacy of photography is admired, no serious photographer shoots B&W anymore. There are exceptions like Salgado and a few others, but those guys are very few.