Look at a photograph of the crowd at the 1923 FA Cup final and pretty much everybody is wearing a hat. Fast-forward a quarter of a century and a rough estimate would be that a little under half the crowd at the 1948 final are similarly clad. Go forward another 25 years to 1973 and although Bob Stokoe, the Sunderland manager, topped off his tracksuit-and-mac look with a trilby, almost nobody in the stands at Wembley has their head covered. In the unlikely event that anybody at the first Wembley Cup final gave the matter any thought, it is doubtful they would have believed bare-headedness would become the norm. And yet over the course of half a century, men stopped wearing hats. Things change, often unexpectedly, and aspects of life we take for granted can drift away, almost unnoticed. Football today, as David Goldblatt argues in The Age of Football, is the most universal cultural mode there has ever been, consumed avidly across the globe. It is everywhere, a badge of identity, a tool of dictators, our universal entertainment. But could there be a future in which that supremacy wanes? The Real Madrid president, Florentino Pérez, keeps telling us that football is losing ground among the young but, given his assertion comes amid his advocacy for a European Super League and his reluctance to release whatever data demonstrates his claim, it’s hard to know how much credence it merits. What is clear is that, across the pyramid, more people watch football now in the UK than ever before, that television rights deals have never been higher and that, even if Fifa’s claim that 3.572 billion people watched the last World Cup final is obvious nonsense, it was the sort of number that could be bettered only by a presidential assassination, a global charity concert or a human walking on Mars. But nothing lasts for ever and, as we approach a World Cup so morally questionable that some are refusing to watch, it is worth asking what it would take for football to lose its dominant position. Most cultural modes fade because of technology. Music hall and theatre yielded to radio and cinema, which yielded to television, which may now be in the process of yielding to streaming platforms. Newspapers quake before the internet. Even the hat declined with mass car ownership as people spent less time outside. Yet technology has, by and large, only enhanced the grip of football on the global culture. First radio and then TV have spread it throughout nations and then the world. The expansion has not been without consequence: the fear until the 90s was that broadcasting games would lower attendances at grounds. Absurd as that may seem in the context of the modern Premier League, it has proved apt in many other countries where the preference is to watch the big European leagues on TV rather than attend matches. Social media has ensured the conversation about football goes on, the banality, offensiveness or delusion of much of the discourse less relevant than its volume. Perhaps Pérez is right and the younger generation are all too distracted by TikTok and Fortnite to bother watching Real Madrid hammer Real Mallorca or Elche but, without seeing his evidence, it doesn’t feel like that. But sometimes phenomena do just lose popularity. Discussing Elon Musk’s troubled takeover of Twitter, the tech strategist Gareth Edwards outlined his theory of the “trust thermocline”. A thermocline is the narrow transition layer in a body of water between the surface, where waves keep the temperature relatively warm, and the much cooler water below. It is where the temperature suddenly plummets. Edwards’s theory is that a social media company, say, can tick along, making money, riding out small increases in cost or diminutions of service until suddenly a critical mass of frustration is reached and users desert the platform, after which it’s almost impossible to restore trust – not least because users have migrated elsewhere. “The greater the role emotional engagement plays in the product,” he explains, “the bigger the risk of a catastrophic loss of trust.” Hats, having been essential to keeping warm, became largely decorative and so their symbolic significance became more apparent, particularly to a generation whose wartime service had made them resentful of the status they conferred. It becomes far easier to reject those tokens of rank when your head’s not cold and lots of other people are also rejecting them. Could something similar happen to football? Consider this World Cup. There is disgust at Fifa’s corruption, at the sense of greed, at the perception of the game being used as propaganda. If the football is poor (and given issues of fatigue and lack of preparation time that is a clear possibility) and the experience on the ground – the expense, the absence of games from local television, the lack of recreational options in a city crowded with visitors, intrusive policing – no fun, might that temper enthusiasm for attending tournaments? Could a lack of atmosphere, drabness on and off the pitch, then lower TV audiences and thus broadcast revenues? Perhaps, although it seems a long way off. But then if Conmebol nations are, as has been suggested, admitted to the Uefa Nations League in 2024, there would be a clear alternative to the World Cup, a space to migrate to. In the club game, the case the European Super League three have brought against Uefa under competition law represents a potential risk. If Uefa’s position is found to be a monopoly, could there be a splintering into multiple jurisdictions akin to boxing? Then there would not only be spaces for fans to migrate to, but a dilution of the product – and however dubious the way the modern Champions League distributes wealth and enriches the already wealthy, the product itself in its latter stages is of undeniably exceptional quality. Any threat to football feels improbable, but that’s the nature of thermoclines: when the temperature drops it does so abruptly. The current hegemony should not be taken for granted. Football remains extraordinarily popular but this World Cup may test that. And no cultural mode can afford to ignore the fact that men do, sometimes, stop wearing hats.