“A little more than a dentist and a little less than a psychoanalyst,” was Henri Cartier-Bresson’s reply when asked how long a portrait sitting would take. Seventy-five years after his first exhibition in 1933, what is left of our edgy uncertainties about photography’s power and intrusion in an age when 2,000 images are added every minute to the photo-sharing website flickr.com, and refashioning mobile phone-snaps is a playground pastime? Is the photograph so ubiquitous as visual wallpaper that its role in art, or in the museum, is threatened? And is any of this a reason why Tate Modern’s photography exhibitions are always jinxed?

Cruel and Tender in 2003 was chaotic, Robert Frank in 2004 misrepresented, Jeff Wall in 2005 undervisited, and now the new show Street & Studio: An Urban History of Photography is a sprawling mess. Not a vivid, enticing, mind-expanding mess, like life on the street, but a flat, meaningless jumble where masterpieces are squandered into incoherence, tiny images are dwarfed in towering galleries, colour prints over-glare at delicate monochromes, and rubbish is elevated to drop-dead-dull monumentality.