There are a lot of reasons why a London home that was 300,00k in the 1970s is now worth three times that. More people are living in London now than then, and due to London's "green belt" policies and height and zoning restrictions, there just hasn't been a great supply of new houses.
Tom doesn't even mention things like the oil shock, the impact of technology and automation, or demographics. It's kind of hard to get a reasonable picture of the economy without considering these things!
I agree with the basic point that we should have more Keynesian spending, but the history felt like a distraction. Calling the 70s a "golden age" is just... what is this, I don't even. Yeah, with the Vietnam war, OPEC, Silent Spring, and the threat of nuclear war, it was a real picnic...