> Somehow ELL students are seen as “behind” the native speakers when that’s only when you measure them in English.

I saw this first hand growing up in San Jose in 1970's 1980's. The Vietnam war ended followed by the Cambodian genocide as a result there was a huge influx of refugees and their kids. You had 8 year old's who had spent the last four years in a refugee camp and speak no English at all. I went to college with a bunch of them. They were smart but always trying to catch up with English and writing.