A consensus is building around the case of Meghan, Duchess of Sussex v the Mail on Sunday: even if she wins, she still loses. This is different to the argument by the newspaper, which disputes her copyright claim over the contents of a letter, and which, in response to allegations that her privacy has been traduced, has floated the public interest defence: people have a right to know the nature of her character.

This is not expected to stand up in court, but that isn’t even half the story. Even if Meghan were victorious, she might have watched her own father give evidence against her. She might have had to appear in court herself, as could Prince Harry. She would have spent a vast amount of money, possibly running into millions (it is never plain to the layperson how the bill mounts up the way it does, but high-profile privacy cases can be especially expensive. The pianist James Rhodes, who fought for his right to publish a memoir, described his legal bills as “the length of phone numbers”). To allow such scrutiny of her own life and, inevitably, her marriage, as well as possibly the royal family as a whole, will permanently damage her standing in it. Every royal walks that tightrope – having to be human and relatable, while at the same time subsisting on deference – by being amiable but remote. Would any of their reputations survive if we knew half as much about their conflicts and intimate relationships as we might, even without wanting to, discover about Meghan’s?

However, there is considerably more at stake here than the image of the Windsors, individually or en masse. The tabloid press has always had the working assumption that no royal would ever do anything to jeopardise the institution, so there was unlikely ever to be much blowback, whatever was printed. This is demonstrably untrue for Meghan, who made a choice previously thought impossible: to walk away from the public role rather than swallow the vilification it brought with it. This destroys the public interest case for publishing her letters and texts, but it also explodes the foundation of the media’s relationship with the royals, in which they were treated as hostages to their own respectability.

More important still is the racist overtone to much of the criticism the duchess has received. It is dispiriting to watch journalists make excuses for this – it’s not because she’s mixed race, it’s because she’s American; it’s nothing to do with race, her celebrity from a previous life made her uppity. The difference between the treatment meted out to the two duchesses, Kate and Meghan, especially while they were pregnant, is absolutely chilling. So much of the bizarre, contradictory criticism levelled at Meghan (why is she flaunting her bump; why hasn’t she been seen out and about; why is she keeping Harry away from his family?) distils into: why does she exist? What right has she to inhabit space? If you think seriously about the disconnect between the scorn poured upon her, and anything she’s actually said or done to warrant it, it’s quite a shaming picture of the vindictiveness of the British press towards ethnic minority women.

She has become a battlefield in a culture war, something for Piers Morgan to sound off about, a vegan sausage roll in human form. It is a fantastically unenviable position to be in, but it is also one in which she could not have stayed neutral without being trampled to dust. Silence in the face of this would not be dignified: it is both courageous and vital to object to it, whatever the cost. The consensus is wrong, diametrically so: even if she loses her case against the Mail on Sunday, Meghan will still have won.

• This article was amended on 21 January 2020 because an earlier version used the term princess when duchess was meant.

• Zoe Williams is a Guardian columnist