In spite of the continued decline in the labor force, I would argue that it is quite possible not only to maintain the current level of per capita income but also to realize a new stage of economic development, if technological progress accelerates and/or economic efficiency is improved.
In this regard, economies have the flexibility to respond to demographic changes such as a population decline or population aging. A shortage of labor supply will be at least partly neutralized by increases in the labor force participation rate, induced by, for example, rises in wages.