You’re right, it is exhausting. All of it all of the time. Shonda has her own list of issues within the black community, especially where colorism is concerned on light-skinned vs darker-skinned. Also, not super important here, but if we were going to address the skin tone of Queen Charlotte, historically, she’d be even lighter. Closer to a Sinbad or a Meghan Markle than who they actually used. Anyway, I’m going to address some of your points:

1. Netflix chose Shonda, etc… Herein lies the problem, yeah? The entertainment industry is token “woke.” They follow by “popular” ideals, many times which only scratch the surface to appease the majority public. It’s not actually a full digestion of the issues at hand. Very few Hollywood producers and directors actually “get it.” This includes Shonda Rhimes.
2. As to the Korean version of Suits, et als, these are homogeneous societies in which those shows are produced to appease. America is not a homogeneous society, therefore the rules are not the same for American entertainment. When America adapts Asian movies and shows for an American audience, they cast differently to appeal to their audiences. For example, The Grudge was originally Asian, but when it came over to America and was set in a backwater little town, that cast became not Asian. Additionally, your examples are all of MODERN pieces, not a period piece. Jamie Foxx’s Annie? Modern. Jaden Smith Karate Kid? Modern. That is the major difference here. We’re not talking about how things translate over to other foreign countries here though. We’re talking about an American produced show that blatantly sticks in POCs into a period piece where that representation is not accurate. It makes it look ridiculous. That’s a whole lot of disbelief to suspend to make it work.
3. Mindy Kaling’s pieces (Four Weddings/Never Have I) are also MODERN. I only brought up Kaling for the fact that her casting felt natural and not forced into tropes and stereotyped sidekicks. If Mindy ever did a remake of Pride and Prejudice in 1810 England and cast an all Indian cast WITHOUT reinterpreting the story line to make it appropriate (because Indians did exist in 1810 England) and just willy nilly made an Indian guy an English Duke, I’d call her out on it too. Not accurate. Not appropriate.
4. Shonda’s casting of POCs for MODERN set dramas on TV is notable, however, this is a different animal altogether. One of the most frustrating things about being a POC that is other than black is not being heard or seen by white AND black people. I say again, if you’re going to bastardize someone else’s heritage and customs, then do it openly for all. If you only do it for one, are you any better than the exclusive snots that you proclaim to be against? After all, are we all really equal if some of us are MORE equal? Privilege isn’t just white, you know — particularly in Hollywood. With power comes the ability to change, but if you only serve just yours then don’t expect everyone else to rally their support behind you when you need it.
5. Your perception that the biggest racial reckoning in American society is between black and white is because all other POCs aren’t heard. It is this segregate idea that it is a fight between just white and black people that turn off all other POCs. We’re literally ignored unless our struggle fits a narrative that is familiar and comfortable to white and black people. Misery is not a competition, but American history is edited to to fulfill a narrative. I’ve spent my time on the front lines standing shoulder to shoulder with black folks marching for BLM. I’ve stood up for black men when they were being harrassed by a white cop. But you know what breaks my heart here? That they don’t see me. They see the stereotype of me, but they know nothing about the race issues that my people have had to deal with from both the black and the white community. They assume that I am Japanese or Korean or Chinese and that I’m privileged. We want to support black folks in their struggles because we’ve been there too, but if black people won’t see us, can’t see us, and instead tells us that we “don’t know what it’s like” or that they “suffer more than we do,” you’re going to lose a lot of POCs that would have otherwise been allies. Even now, on black forums and in black circles, many times when you ask them to point out who is a POC, Asians are left out of that selection. They only see what the media represents of us…pale, tiny, effeminate. They don’t see the diaspora of what is truly Asian. Asia is the largest continent in the world, yet so many people think that we’re all East Asian.
6. Lastly, for a romp and light-hearted show, Shonda did okay. Amazing is up to interpretation and is subjective. She had to know that putting in a black cast (and ONLY a black cast with her white cast) would stir up some controversy. Maybe she was expecting it from white people and not from another POC, but from a person who’s people have struggled to be heard since we set foot in this country, her choices leaves a lot to be discussed.