Most water companies in the UK will not allow you to start a new flat rate tarriff though (and will definitely be applying pressure to those on a flat rate to get a meter). So if you move house chances are you will get a meter installed straight away if there isn't one already.
I've never stayed in a place in london with a water meter, and I've lived in 5 places over 8 years. In addition we've tried to get one fitted multiple times, as it was becoming mandatory. None of the places I've lived in were able to have one fitted, as in large buildings fitting a meter for each flat is simply not possible, especially in old council flats.
In most of Quebec, water is not billed nor metered. It's considered as a "public good" and paid for through property taxes. That does lead to overuse and waste though.
Chicago also, at least historically. On the shore of Lake Michigan, there is no lack of fresh water. It was billed however. You paid a flat rate for water service, but it was unmetered. I'm not sure how much this is still the case.
It's not the default. You cannot buy a new house today without being on a meter. That is the default.
It's just our housing stock being so old and decrepit, where nobody can be bothered updating anything even if it's provided for free by the utility companies, that the majority of houses simply do not have a water meter!
There's a general sentiment that smart meters and metered water will make costs skyrocket or somehow hold you ransom to abrupt and unfair price changes, as if that somehow wasn't the case today...
