Gregory's Server
Mixer taps aren't that common here but you will see them in kitchens and bathrooms more then you used too.
The main reason is that the water supply for the hot water system wasn't generally considered safe to drink.
In many homes there were water tanks in the roof space to feed the hot water heating system. Poorly covered and sitting in a header tank isn't a recipe for water safety 🫤🤷♂️