My wife has become one of the latest victims of a British tabloid press that wages campaigns against individuals with no thought to the consequences,” wrote Prince Harry as he and Meghan, Duchess of Sussex, launched legal action against the Mail on Sunday for publishing a handwritten letter she had sent to her estranged father.

I am a lifelong republican but reading Harry’s letter, I found myself practically cheering. Seeing the red-tops turn on Meghan Markle over the last year has been like watching a type of abusive relationship from afar, in which various gossips have worked with the worst parts of the press to relentlessly harass, bully, and vilify a new mother. Royal hangers-on will talk of how speaking out in such terms is an unprecedented move for the monarchy but Harry’s letter is powerful because it is human; it is the words of a husband who has watched the wife he loves suffer and has finally had enough.

The royals are, in many ways, caught up in a devil’s deal with the media: their very survival depends on positive public opinion – and they are happy to play to the cameras to get it – but the price for that gets ever higher and some reporters push the boundaries past any recognisable form of decency.

That Meghan is mixed race and her only visible family member – her mother – is black has added an edge. Even before the pair were married, Harry’s communications secretary issued a statement deploring the “abuse and harassment” of his then-girlfriend and “the racial undertones of comment pieces”. There are multiple valid grounds on which to criticise the monarchy – say, its use of public money to renovate its luxury homes – but the relentlessly negative press on everything from “flaunting her bump” to sending emails too early in the morning goes far beyond this. Harry’s openness about his mental health struggles in light of his mother’s death, and the media’s focus on her, give it even more resonance.

The reason that Harry’s letter touches such a nerve is not only sympathy at what the red-tops are doing to the Sussexes – but that it is an extreme example of what they do to thousands of others. The Leveson inquiry back in 2011, sparked by the phone-hacking scandal, was meant to be a turning point in the ethics and culture of the British press but it increasingly feels as if nothing has changed.

Last month, the former Welsh rugby star Gareth Thomas was forced to reveal he had HIV after a newspaper threatened to publish it; he says a journalist even told his parents of his diagnosis. This came within days of the Sun printing a front-page splash about a historic family tragedy of the England cricketer Ben Stokes, a move he described as “disgusting” and “immoral”.

These stunts are nothing more than bullying as a form of journalism, a tactic that is not just saved for the rich and famous. Read through these papers’ coverage of disabled people or immigrants over the years and you will know they are equally at home targeting the powerless.

The worst part of it is not only that there is such toxicity in sections of the press but that their actions appear to carry no consequence. A decade ago, I remember feeling sick reading Jan Moir’s homophobia-laced column for the Daily Mail on Stephen Gately’s death and yet in the years since, the paper has continued to ditch basic ethics. The industry with the greatest capacity to cause harm often feels like it has the least accountability.

A newspaper known for its immoral tactics being taken to court holds a significant message to the editors who make money this way. As Harry himself said: “There comes a point when the only thing to do is to stand up to this behaviour, because it destroys people and destroys lives.” That goes for the royals, a rugby player or a benefits claimant.