While I'm inclined to agree with your point and I do think that some languages really are just more difficult, I think it should be pointed out that something like 54% of adults in the USA read below a sixth grade level. Many of them (about half) are functionally illiterate.
Thankfully, while your first assertion is (sadly) accurate, your 2nd is not. From the wikipedia article you cited:
> "Literacy in the United States was determined by the National Center for Education Statistics to be at a mid to high level in 2019, at 79%, with 21% of American adults categorized as having "low level English literacy," including 4.1% classified as "functionally illiterate" and an additional 4% that could not participate.[1] According to the U.S. Department of Education, 54% of adults in the United States have prose literacy below the 6th-grade level."
The second claim comes from something I heard mentioned the other day in relation to a New Yorker article about parents finding out during covid lockdowns that their elementary school kids couldn't read hardly at all. I guess they've changed the teaching styles so kids don't really learn like most millenials did.
FWIW, here's what I was found on Google:
> According to the National Center for Educational Statistics (NCES), 21 percent of adults in the United States (about 43 million) fall into the illiterate/functionally illiterate category.
> "Literacy in the United States was determined by the National Center for Education Statistics to be at a mid to high level in 2019, at 79%, with 21% of American adults categorized as having "low level English literacy," including 4.1% classified as "functionally illiterate" and an additional 4% that could not participate.[1] According to the U.S. Department of Education, 54% of adults in the United States have prose literacy below the 6th-grade level."
Functional illiteracy is more like 4-8%.