many of those “tenements” if you will have been gentrified beyond recognition, or knocked down…

That happens here, too. Such houses can be well-maintained, modernized £500,000 properties if they're in the right location. These were not in such a location - the street was, and despite massive improvements still is, a refuse-strewn shitpit full of boarded up windows, grafitti, leaks and other damage. It got so bad at one point that the government were literally giving the properties away for free to anyone willing to repair them.