Again, this is all about proper civil engineering and city planning. There is nothing inherently impossible about supporting billions of people and there are wide swaths of India with barely anyone at all.
The earth is a gigantic place. Every single human would fit into a cubic mile. The amount of freshwater that every single living creature drinks is only a sphere of a few miles in diameter, which itself is less than 1% of the freshwater on the planet.
The capabilities are vast, we are not limited by numbers but only by the weaker parts of human nature.
Your first statement speaks to the larger "disrupt everything!" naivete found in spades on Hacker News, and I imagine, by extension, in Silicon Valley.
Sure, wave a wand, and POOF! No more greenhouse gases. Wave a wand, and POOF! No more single-use plastics. Wave a wand, and POOF! No more dead bodies in the Ganga.
That's not the world we inhabit. The world we inhabit moves at a glacial pace, and I sincerely doubt India moves at ALL.
The fact that humans can all fit into a small cube says nothing. Or at least, says far less than the fact that in India, the cities are in squalor and resemble garbage dumps much more than they resemble thriving metropolises. And that's NOT hyperbole.
What, exactly, has improved in our cities that leads you to your optimism? The fact that Delhi is the least polluted city in the world? Oh, wait. Or does your heart glow with joy while taking long walks along the banks of the Ganga, breathing in the smells of nature?
Hypothetically, anything can be done. In reality, the only part of your argument that matters is the rather poignant last statement. Optimism is for other people. A large order of deep-fried cynicism for me please.
The original comment was blaming overpopulation, but that's simply not an issue as I've explained. There are very dense cities that look and work fine because of proper planning and infrastructure. India can do this once it gets over the corruption and outdated politics but it will take time, but again has nothing to do with population size.
I'm not sure what argument you're trying to make but optimism has nothing to do with the discussion.
The earth is a gigantic place. Every single human would fit into a cubic mile. The amount of freshwater that every single living creature drinks is only a sphere of a few miles in diameter, which itself is less than 1% of the freshwater on the planet.
The capabilities are vast, we are not limited by numbers but only by the weaker parts of human nature.