Nobody gets blisters from signing too many contracts. Equally, from wearing Tiffany jewellery. Unless it is that knock-off stuff laid out on street corners. And even then it is more likely to turn your wrist green than cause lesions.
So we can presume Emma Raducanu is working hard on retaining her US Open title. Very hard. And yet it is not enough. For some people, it is never enough. Whatever she says, whatever she does, the narrative stays the same. Flash-in-the-pan Emma got lucky and, since, has been more interested in clinching commercial endorsements than working on her game.