I square it quite easily.
DS goes to a couple-ed (it used to be single sex but went co-ed in 2020), and DD goes to single sex.
I think boys benefit from not being in a single sex environment, and I think girls benefit from being in one - at least for the few hours of the day when they’re learning.
I went to a single sex high school (years 9-13) and loved not having to think about, be pressured by and over-talked by boys. I remember getting felt up by boys at the age of 11 in the co-ed school I was at before I moved. 11.
And at that school, all the talk was about boys and who liked who, and being aware of them all the bloody time.
It was a relief not to have that.
School is only a few hours a day, and most girls have brothers, fathers, cousins, family members and friends of the opposite sex that they regularly see and spend time with outside of school.