Look at p13, I and others discussed it in some detail.
The Firm is set up to protect the monarch and direct heirs, and everyone else exists to support and boost them. Nobody is allowed to outshine the heirs (the smear campaign against Diana started because she was more popular than Charles). Married-in royals get thrown to the wolves as a test of loyalty. Kate has protection now because she kept her mouth shut during the years the press were brutal towards her. Harry and Meghan failed the loyalty test by insisting on protecting their children, rather than letting them become props in a toxic and racist system; they had to be punished for that, and punished to send a message to anyone else thinking of leaving.
There's an agreement between the press and the RF, the RF give the press stories in exchange for being allowed a certain degree of control over the narrative. Sometimes this is basic stuff like "if we give you regular access to our kids, leave them alone the rest of the time." Some of the time it's "we'll give you scandals on minor royals if you kill scandals on the heirs."
This happens all the time in every area of public life. It's extremely common for talent agents and publicists and especially record companies to leak scandals about less important clients, in order to protect more famous clients.
The royal tabloid machine feeds on scandal because that's what sells papers. At least one royal has to be the designated headline-generator. It was Margaret, then Diana, then Fergie, then the York girls, then Kate, then Meghan. Have you not noticed how negative articles about William and Kate have ramped up since Harry and Meghan left? Today alone there are goady tabloid articles hinting that Kate has an ED, and a big article in the Mail slagging off Will and Kate for exposing their kids in the public eye so much. Because someone has to take H&M's place as designated family tabloid whipping boy.
The RF don't have total power over the press, but they can decide who is protected and who isn't. Heirs get protected. Blood royals get protected over married-ins. Compare the non-stop hateful coverage of Meghan during her pregnancy when her only crimes had been "eating avocados" and "wearing nail varnish", with the coverage of Andrew for using royal money to pay off a raped minor. When Sophie Wessex (I know she's a married-in but also supposed to be close friends with the Queen and the Queen's favourite) was caught on camera selling access to royals and slagging people off, the Queen personally intervened to ask the press as a personal favour to leave Sophie alone. No such protection for Meghan.
It's pretty obvious the RF were leaking like mad about Harry and Meghan, the Jason Knauf and Melissa thingy case alone is absolute proof of corruption, and it's pretty telling that the RF were releasing damaging stories about Meghan at the same time they were doing everything in their power to stop the press reporting on William's alleged affair with Rose Hanbury.
Harry was born to be the sacrificial lamb because that's what second borns are within the royal system. The Cambridge kids are still small yet the press are already creating personas for them "mature and well-behaved George vs naughty Louis" exactly like how William and Harry were painted in the press when they were kids (which by account wasn't even accurate). I guarantee in 10-15 years the press will be outright demonising Charlotte and Louis and creating scandal out of whatever normal teenage things they do, while still painting George as an angel, and no one will question it because we've been reading that George is the good one and Louis the brat since they were tiny.
Look at the terrible press coverage when Harry was a youth, even as a tiny kid the press would regularly paint him as naughty and rambunctious, as a teen it got even worse. There are lots of alleged incidents where William's involvement in things was covered up, or photos of Harry leaked to the media but not similar photos of William. Books written about royals (like the feuding brothers one) have contained some shocking allegations about Charles giving the media damaging photos and stories about a then-underage Harry as part of a quid pro quo for them to kill damaging stories about himself or William. The RF could easily have protected Harry and they would have done if he'd been born first.
The RF also use the press to keep people in line. "Do as we say or we'll smear you in the press" is a pretty powerful weapon of control. How often have we seen royals step out of line, even in a very minor way (like Eugenie making sure she was seen with Harry at a high profile event in California, making a very public statement of support) followed immediately by some negative story or leak in the press? Who leaked the yacht photos of Eugenie's husband, and was it due to her support of Harry?
And we can't ignore racism, both from the press and the RF. Harry saw the racial component to Meghan's abuse and the racism towards his newborn son (posters engage in racism-denial a lot here but it is a fact that two British Neo Nazis were convicted and jailed for planning to kill Harry for being a "race traitor", and literally three days ago news broke that a white supremacist podcast publicly called for Archie to be "put down" because having mixed blood made him "an abomination" and called for Harry to be executed for treason, for permitting white DNA to mix with black DNA - imagine if people were publicly calling for YOUR children to be killed, if dangerous criminals were being convicted for planning to kill you for having mixed race kids??) He didn't want his child to go through what he went through, because the additional factor of racism would turn an unpleasant experience into a dangerous one.
Now Harry has broken two cardinal rules, refusing to be a sacrificial lamb and putting his children before the Firm, and pulling back the carpet to reveal the grubby agreement between RF and press. He broke a rule so he had to be punished.
His mother did the exact same thing - outshone the heir, then broke the code of silence to talk about how she was gaslighted and emotionally abused. Look what a huge smear campaign they conducted against her, when she could have been the RF's biggest asset.
I think also the agenda behind the original smear campaign was to drive Meghan away. Nobody ever thought Harry would leave too. I believe their end goal was to drive Meghan away and cause a divorce, resulting in a chastened Harry coming back into the fold with his tail between his legs and doing whatever was asked of him as he no longer had anyone in his corner putting his well-being ahead of the Firm. I don't think they'd accept any wife for Harry unless it was someone very passive who wouldn't interfere in the WKH dynamic. Certainly not a strong wife saying "you don't have to tolerate being treated as lesser just because you were second born."