Prices feel like a middle income country, but that is just the Yen sucking. Otherwise it feels very first world.
No it isn't. In purchasing power terms Japan has been, or is about to be overtaken by Poland and Slovakia [1]. This is largely due to demographics and the declining share of the working age population. There is nothing that impoverishes countries more. Gradual decline feels fine for a while, until it doesn't when the bulk of the workforce ages out.
[1]https://marginalrevolution.com/marginalrevolution/2024/07/po...
https://www.pewresearch.org/global/2018/11/12/perceptions-of...
Also, a quick googling suggests both Poland and Japan both have fertility rates around 1.2. Working age of Poland is 65% of the population vs 60% for Japan. So a bit worse.
We've been through this endless times through history. When one ethnic group is exterminated, they are still dead even if strangers move into their land and dwellings. Whether that is done through war, disease or economic strangling of the youth. All has the same result and it is a crime against humanity and a crime against God.
As long as the Japanese are allowed to exist, they can flourish again. Not if they've been replaced by different people. It's the same for all of us in the world.
When you compare Canada, the US or some of the higher immigration countries in Europe to developed countries without immigration you'd wish you'd have price increase problems.
Japan, sometimes hailed as an alternative to immigration is now so poor and old that middle class Westerners travel there like they traveled to a middle income country twenty years ago. If you think Canada is stagnant you haven't been to places where a quarter of the population is aged over 60.
Immigration problems and friction are real but they absolutely pale to the economic disaster that low birth rate aging economies experience. Without significant migration you're looking forward to decades of deflation, politics dominated by people who raise pensions and basically no entrepreneurship. Cultural and housing problems are fixable (just build more housing), dying out is not.