I don't understand why you say these things are opposites.

This one suggests (socioeconomic) class is a factor in lower performing boys' performance. This is true: at least in the US, boys' academic performance is more affected by socioeconomic class than girls' (though both are very much so).

balls187 says that the way boys' and girls' academic performance evolves vs. age is different. This is also true.

Sure, the UK GCSE data has shown a gap for the past 30 years: https://www.buckingham.ac.uk/wp-content/uploads/2019/02/GCSE...

Edited to add: please also see the work from David Figlio et al. mentioned in Krona’s comment below. That’s an interesting study design that tries to demonstrate that boys in aggregate need higher quality schooling to achieve the same level of performance as girls in aggregate.

I don’t think Balls187’s comment is incompatible with mine really – they can both be true, even if the anecdote turned out to hold generally.