I’m my experience of working in 6 hospitals and being a patient in a 7th, none of them have had mixed bags. Mixed wards, yes, but separate rooms for male and female with 2-8 beds in each - known as a bay. I’ve never known anywhere to have mixed bays. Apart from ICU, but the second a patient is declared not longer needing ICU level 3 care they have to be moved else it’s known as a mixed sex breach, which is reported to NHSE and the trust is financially penalised.
the reason we can’t have male/female only wards is because we need to be able to flex based on demand. In my hospital, as an example, each ward is 28 beds, 4 bays of 6 and 4 side rooms. Now that could be 2 male and 2 female bays, 4 male, 3 male and 1 female etc. it is important because imagine if in the female bay, all were discharged, but the only people needing admissions in A&E (in time order) were male, there would be empty beds sat upstairs for hours/days whilst the other sex sat and waited in ED. Quite regularly, we will have 6-8+ of one sex waiting for the next bed in that order, we regularly have to “flip” bays, so move one sex to an empty bed on a different ward and convert what was x sex bay into y sex bay due to the demand.
this is obviously far from ideal as the ward is shared and men can be walking around. However it’s the best we have at the moment.
moving forward, all new hospitals will be built with entirely private rooms (like the side rooms we have now) so no open bays of 2 or more beds with curtains round. But there will still be mixed sexes on the ward. Except on specialty wards such as gynaecology/maternity obviously.
not ideal, not perfect but hope that explains the logic a bit