Yes (and you can take that argument to deliciously absurd levels by pointing out that eventually humanity would have to form a sphere whose radius expands faster than light speed).
But concerning the actual topic at hand, Japan's labor market problems have nothing whatsoever to do with a resource or land shortage.
They probably have something to do with that. At the moment, for Japan has a tiny handful of iron mines [0]. So if they want to produce a steel widget, they have to justify someone transporting the iron either through the Chinese mainland or up the coast, past a lot of people who are learning to do wonderful things with steel. They import a lot of coal from Australia but China has relatively easy access overland from provinces like Inner Mongolia.
I'm not sure how much of an advantage they gain from having very easy port access by virtue of being an island (probably quite a big one, I assume). But it is hard to accept they wouldn't be having a much easier time if they had easy access to something like the Saudi oil fields, the US oil fields, the Chinese coal fields, etc etc. They are a long way away from the good sources of natural resources.
And they struggle to be self sufficient in food in the first result I found [1]. That is pretty different from somewhere like the US. There is a real risk of war in East Asia, so I imagine they'd be quite uncomfortable with that.
They have completely different resource-use problems than the economies that are larger than they are. The idea that the US would have to exert itself to be self sufficient in food is rather weird, as is the idea that China would struggle to justify transporting resources to the country from Mongolia, etc. It is obvious to me what could be done with more people in the US or China. In Japan there is probably something, but it does require actual ability to find instead of just "dig more, grow more, build more, forge more" that their competitors for the best-economy crown can manage.
Japan needs transformative technological improvements to grow. The US needs warm bodies. China needed to stop the Great Leap Forward and put competent leaders in charge. The Japanese challenge is much greater.
Japan in the 1980 didn't have any better access to natural resources than it has today, yet it didn't have the labor market problems described in the article. Many, many other countries don't have a lot of natural resources and are not having these problems.
My basic argument is Japan (might have, I did see a few convincing counters in other parts of the thread that were convincing) too many people for the amount of land they have.
Your counterargument is that they didn't have a problem in 1980, when they had less people and the same amount of land. I can't disagree with that, but it isn't relevant.
> Many, many other countries don't have a lot of natural resources and are not having these problems.
They have the 3rd largest economy in the world. It goes US, China and then Japan. 30% higher GDP than the next contender, Germany. If there are any non-linear economic effects at all between size and labour market, Japan is going to find them first.
You may have misread the numbers slightly; population of ~117 million in 1980 and a population of ~ 125 million today.
And the chart in that article shows that they basically stopped having children in 1980 which would be consistent with a "running out of resources" hypothesis as a root cause. If they hit a wall in economic carrying capacity circa 1980 that chart would supporting evidence.
But concerning the actual topic at hand, Japan's labor market problems have nothing whatsoever to do with a resource or land shortage.