I don't know what the data says, but I think this should be answered with data. If results are better with segregated education, go for it. However, I think it

I don't know what the data says, but I think this should be answered with data. If results are better with segregated education, go for it. However, I think it has mostly been abandoned because results weren't actually better. I think I have read about issues with girls only classes, but I don't have the time to google for it now. Especially with respect to STEM it seems easy to check how many girls from segregated schools go into STEM vs girls from coed schools.