We will almost certainly be choosing a girls' school for DD. As @UnimaginableWindBird said, girls' schools are an environment where 'female' is the default, in a world where the default is still very much male. The Head of a lovely girls' school I recently visited opened her talk with: 'This is a place where girls take centre stage', which is exactly what I want for our daughter.
I attended a coeducational grammar myself, and would be fine with a mixed grammar environment, where the common factor among all the students is that they love learning and want to be there. But in a comprehensive setting I think other factors kick in that are potential detrimental to girls and their learning.
I currently volunteer in an upper KS2 class at DD's primary, and to be frank the class I'm in is an excellent advertisement for girls' schools - frequently at least half the lesson time is wasted due to low level disruption from disengaged boys, many of whom have unmet needs and cannot function properly within a mainstream setting. Obviously this is symptomatic of the SEND crisis and in many (though not all) cases isn't the boys' fault as such, but neither is it the girls' fault to sort out, and pragmatically speaking an all girls' school screens out a lot of that disruption and wasted time.
I'm also a primary governor, and in this capacity am very often party to discussions around how to better engage underachieving and disruptive boys in learning - lessons themed around football; focus on wars and conflict in History; class readers written by male authors, with male protagonists. Seldom is this ever reversed; the girls are just expected to get on with it. Even our local mixed comp has got wise to all this, and now teaches girls and boys separately for the core subjects.
The negative, I guess, js the old trope that 'girls' schools are bitchy', frequently trotted out by a fair few people I know. But in a lot of cases this strikes me as internalised misogyny, and I've seen very limited evidence for it myself.