I'm not, there are always extreme outliers and exceptions, but I do believe that the vast majority of children can meet the incredibly low bar for mathematics education that is considered normal in North American schools.
I also believe that teaching them to be afraid of math, (and having their teachers be afraid of math) is a major contributing factor for why so many of them struggle so much to meet that bar.
Speaking of teachers... my own grade-school math development, decades ago, was stunted by the fact that my teacher didn't know anything about linear algebra. I asked her for help deciphering my "Amiga 3-D Graphics Programming" book, and she concluded that the vector and matrix notation must be a bunch of typos. Arrgh!
This is a big one. I was in sixth grade when my science teacher told me that the boiling point of water was 132F, because she thought you added 32 to convert from Celsius to Fahrenheit.
This problem runs all the way down, from teachers colleges to the kinds of people who apply to be K-12 teachers. That fearing math is okay and normal is pervasive in the culture and it’s not clear to me you can even do anything about it other than implement gating math credentials for teachers that would exclude a huge fraction of teaching school graduates.
This is a huge part of the issue I feel. I know way too many elementary school teachers who are afraid of math themselves and struggle to understand it. Is it any wonder the kids they teach don't? It causes big problems when they get to me for mathematics in high school.