Meghan was seen as a great asset.
No that shows a profound misunderstanding of how the British monarchy works.
The RF is defined by one word and that word is hierarchy. Every single thing the RF do is to protect the hierarchy and prop up and promote the heirs and protect them from any negativity.
Outshining the heirs is the number one sin in the Royal Family. It's well-established that Charles was wildly jealous of Diana's popularity and her natural charisma and ease with people, and rather than try to capitalise on those qualities, the RF did everything they could to downplay or dismiss Diana - to try to portray her as stupid, for example - because she'd broken the cardinal rule of outshining the heir.
One of the things the Andrew Morton book discussed was that Fergie became deeply unpopular within the RF very quickly because she was far more outgoing and more of a party girl than Diana, the press loved how outrageous she was, and the fear was that she would make Diana look stodgy or dull or steal press attention from her. Of course no one could make Diana look dull, but that was the concern and so Fergie's light had to be forcibly dulled. (Diana wasn't allowed to outshine Charles but as future Queen no one was allowed to outshine her.)
We've witnessed Kate go from being a beautiful, charismatic and outgoing woman who clearly has a sense of humour, to being basically a docile, subservient Stepford Wife who never steps out of line and doesn't outshine her husband. And I mean it's William. It takes a lot of effort to under-shine a human baked potato.
The other aspect is that non-heirs are expected to "do their duty" in doing whatever is needed to protect the heir. Enough people have come forward to testify that the RF would deliberately contact the press to offer them negative stories about or even damaging photos of Harry, starting when he was a teenager, as a bribe to coerce the
press into dropping potentially damaging stories about William. There's also heaps of evidence of senior Royal aides leaking stories to the press and not only not being fired, but actively being rewarded and promoted for breaking their NDAs and selling out/betraying their bosses, so clearly they were being told to leak stories not doing it sneakily on their own initiative. This is page 1 of the Royal PR Playbook and you can see how they've used this technique over and over again with different people across the generations.
Harry and Meghan were welcomed into the RF - clearly there was racism from the start, clearly not everyone was happy with a senior blood royal marrying a biracial woman, but she does appear to have been welcomed originally.
The two turning points appear to be their hugely successful tour down under, which incited a lot of jealousy and the substantial and legitimate fear they were overshadowing William and Kate, and needed to be reminded of their place. This is the exact same thing that happened to Diana.
The second was William's (ALLEGED) affair with Rose Hanbury, which we know William and KP had an explosive reaction to (William claiming his human rights had been violated and unleashing his full legal arsenal against the press. If you look at the timeline certain specific negative stories about Harry and Meghan were leaked to the press at the exact same time the press were being ordered not to report on the Rose Hanbury story. It's pretty clear that Harry and Meghan were being used as sacrificial lambs to protect William and act as a distraction, again this is Royal PR Playbook 101, and it's clearly something Harry and Meghan refused to tolerate.
The RF don't care what qualities a person has. There's only one thing that makes someone an "asset" to the RF and that's being subservient and willing to do as told. Clearly that's not Meghan, and it used to be Harry but it's not anymore.