Dozens of advertisers will flock to Super Bowl LVIII this Sunday, ready to pay out a small fortune to CBS in a bid to grab some attention. But they won’t crave as much of that valuable recognition as they might have just a few years ago. The Super Bowl has long offered Madison Avenue an arena where risk taking is welcome. In 2015, for example, Nationwide ran a commercial during Super Bowl XLIX that told a story from the viewpoint of a child who was already dead, while the portable-power company Mophie offered a spot showing God letting the Earth...