Automation, increased productivity continue to rise at least as fast. Not clear we won't be fine simply because of that.
And No we do not have to chase the Malthusian Catastrophe to 'win'. We can do it other ways. Quelling consumerism. Reigning in capitalism. Sensibly designing cities.
The Japanese talk only of extinction of the pure Japan, which is on the face of it a racist policy. Not a real strong point in the argument. Japan will persist, with a normal mix of people from around the world creating a new culture that they want. Not something frozen in time that the octogenarians of Japan worship and cling onto.