In Oklahoma, the requirement usually is up to “algebra 2” - this is mostly domain and range, finding roots of polynomials, and logarithms.
IMHO, the world would be better if calculus was a required part of the high school curriculum. Like yeah, most people aren’t going to need the product rule in day to day life, but the fundamental ideas about rates of change seem like they’re something that everyone human deserves to be exposed to.
I’m certified in special education and spent two hours of my day today teaching an adult how to do subtraction. I’ve worked with kids with Down syndrome. I entirely believe that it would be possible for 95% of students, if given the appropriate support, to learn how to take a simple derivative and have some vague understanding of what they did. It just takes visuals, good use of real world examples and metaphor, and patience.
Believe the problem is the appropriate support part. Most teachers are struggling with keeping kids off their phones and trying not to get killed in reprisal. Classroom size, low wages and burnout are at all time highs.
Looking at the state of the US right now, calculus wouldn’t be where I’d devote my energy.
I have family working in Special Education, most of them with kids under 12, some through early adulthood. All your points are correct. But from what I know of US Education, most schools - or schools in certain states - will not receive appropriate support and the students will ultimately be hurt for it. Think of the implementation of Common Core in the mid 2010s.
Students with proper support and encouragement can accomplish amazing feats, but most students don’t have the resources to do that on their own (or with limited support and instruction.)