I think that both in your mind and in the minds of those objecting, there's significant muddling of the cultural appropriation issue with faithfulness to source...so I guess I can't object too much if you're responding to the muddle.

I do think the two are worth addressing separately, however.

Most of the changes in Jackson's adaptation were, to my eye, bad--I too have reread the books frequently (not quite as often as once per year), and I do this because I love not just the scenery but also the nature of the tale. The adaptation was quite faithful, and in that it is enjoyable. But hasty ents, rushing to war upon discovering that they had no idea that Sauron was destroying the trees under their care? The Witch-King breaking Gandalf's staff--the physical representation of his power and authority--when the whole point was that Gandalf 2.0 had far greater power and authority than anyone realized? Turning the Army of the Dead into a Defeat the Enemy For Free card, instead of it merely assisting a local victory thereby freeing up the brave people of Gondor to save Minas Tirith themselves? A repulsive and inept Denethor instead of a great man deluded by a skewed perspective and broken by grief? Aragorn murdering the Mouth of Sauron instead of treating even the most repulsive and arrogant emissary of the Enemy as an emissary? And so on. These were not necessary for adaptation to the screen. They were simply a difference of vision in storytelling, where Jackson preferred surprise and a combative romp, while Tolkien preferred nobility and reflection.

Jackson's movies bothered me--maybe not you, but they bothered me, even though I liked many aspects of them. And it is in that context that greater concern over Amazon's efforts in what they want us to believe is Middle Earth are suspect. It is worth separating the "this is unfaithful" comments, which you get from every devoted fanbase about every substantive and unnecessary change to setting (skin tone included, when it is known, and absent presentation of lineages showing why the appearances make any sense) from the "I dunno what Sindarin is but I don't wanna see any black folk on my screen, you hear?"-type comments.

You seem to be replying mostly to the latter, and I've seen them too, and they're kind of disgusting. But mostly I've seen the former, and Amazon seems in its trailers to have gone out of its way to raise rather than assuage concerns. ("Here's Arondir's lineage!" or "Elvish skin color isn't inherited but rather ____!"; "Miriel doesn't look terribly much like her first-cousin Ar-Pharazon and seems substantially younger than him not a year older, but you see...".)