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...