Yeah the sheer scale of this area shows a time of very strong industrial strength. The collapse of the USSR and the following globalism definitely killed it off in most nations. It's a tragedy given how many people would've relied on the income to survive. As well as having some pride in the nation due to it actually being able to sustain itself.
I think there's a strong correlation between industrial scale and nation happiness (in most, not all) nations. In the west everyone associates the decline of their land with the collapse of industry, where nothing is made anymore and the patriotism is gone.