Japan is shrinking. Tokyo, however, is growing. It would not be good news if our cities had a glut of housing. We have three billion people of rural->urban shift we still need to do.
Localized growth has nothing to do with total population.
These urban housing crises in every major western country have nothing to do with population growth and everything to do with population concentration.
We should expect this problem to accelerate during periods of population decline, because there will be even stronger economic incentives to move into concentrated population centers.
This is not sustainable. The good news is that, due to demographic shifts, we might have a glut of housing in 20 years.