Standard of living for whom? He's looking at a particular example, from a particular social class, from his own particular experience. The statistics (which are often not generated by 'the government', but by academics and independent economists) are general.

They're not talking just about middle class people, it's quality of life across the board. I also love how he dismisses the internet and mobile phones, as if people from lower socioeconomic would have been able to afford them had they existed in the 1950s. Has the standard of living for every single family improved since the mid 20th century? No. Has it improved for the majority of people? Yes. Standard of living isn't signified by how many cars you have, it's dependent on things like the number of children who die before turning 5, how many people have access to electricity 100% of the time, education, and the internet.

I think he's selling a viewpoint to a particular audience, and I think he's very convincing. Interesting post!