We all want what we don’t have I think. I’d say the provision for secondary schools where I am is 50/50 mixed sex/single sex in ROI.
We have mainly single sex in my town as an example. It is not the blissed out panacea you’d hope for.
I have sons and daughters and the boys have a much much better school on every possible level and have done for decades. This can go the other way in other towns.
The girl’s school here for example are less invested in wellbeing, less expectations of achievement, education outcomes are far worse.
These are girls whose brothers are in the boys school so level for every socioeconomic factor, home life factor etc etc.
There are less science subjects and subjects in general available for girls in the girls school but that translates across the country as practical subjects (woodwork/metalwork/technical drawing/ technology/computer science/Physics/applied maths) are not taught in girls schools to the same numbers. They just would not have the uptake to support it in the school so they are not taught .
This town has been crying out for the schools to amalgamate for decades. It will happen and most parents will be thrilled.