Everyone who has been to Japan in the last 20 years or so could argue about the quality of life. Japan is not quite "shiny" and people are not rich.

Japan is a monoculture that acts almost like one big family. Economic rules and values kinda go out the window similar to the way they do when you are selling your brother your old car or repairing your grandmother's sink.

There's a saying in economics:

"There are four types of economies: developed, developing, Argentina, and Japan."

One must be very careful drawing conclusions for other societies based on Japan as a sole example. I somewhat agree that Japan illustrates that massive infrastructure investment, combined with diligence in maintaining functioning societal systems, does in fact yield a high quality of life that appears sustainable even if the metrics of economic growth look terrible. That's because GDP as a measure of "quality of life" is a shitty indicator IMO, but that's a whole 'nother rabbit hole to go down...