I'm sure you all spoke and could understand english, too.
But many of us came from parents who did not speak English well.
My class size was over 45 every year in grade school.
It was 35-45 in high school. There were no "classroom helpers". There were "special needs" children.
Nearly all of us graduated, and a huge proportion ended up going to college.
Small class sizes are, if anything, detrimental to education. Students are discouraged from working to better themselves, whether in language or understanding. Self reliance is the most important skill you can be taught in school, and large classes encourage that.