Gob-smackingly ill-suited to the small screen, Gus Van Sant’s infuriating and addictive road movie is a tale of two Gerrys (Matt Damon and Casey Affleck) lost in the desert. It’s also a sumptuous Utah travelogue. And a pompous Beckettian comedy. And a sly parable on human frailty. But by then you’ll have switched off the TV.