And ignore the "GDP" stuff. You will read the same about Italy in English language newspapers. And (South) Korea. Both are also beautiful countries with great food and very high quality of life.
I look at overall GDP less than GDP-per capita. The best metric in my mind is historical median salary. This gives a great idea of how middle class people live. As long as it holds steady and inflation is zero, then quality of life does not decline. The truth is that Japan has microscopic growth (~1% per year) combined with annual population decline of ~0.5% per year. Those two together should mean quality of life is still increasing a little bit each year. And, yes, each year that I return to Tokyo, I feel it is still improving.