Most of the "controversy" is because rather than memorizing rote formulas that most of us end up forgetting, a lot of the ethnomath focus is on critical thinking and practical applications. Like, great if you can remember PEMDAS and whatnot, and I'm sure it'll be useful from time to time as an adult but considering we all have literal calculators in our pockets all the time it's not really the most important thing to learn anymore.
Math may be universal, but the way we teach it and the way people learn it isn't.
Your posts are still nigh indistinguishable from a Fox News op-ed, and just as poorly sourced given that all the "evidence" you've used to back up your claims so far hasn't actually done that.