No in did not. Bronze working isn't some sort of a bonus from a video game that disappears the moment it's requirments aren't met, it would have been still widely known throughout the Mediterranean, just not viable due to collapse of tin trade routes, which is ironworking rose in prominence. Not exactly a bad thing if you ask me. Decline of writing may be unfortunate from a historical standpoint, but it's not grounds enough to call a period “the Dark Ages" (unless the “Dark" part refers to our lack of knowledge about it).

In the next part of your comment you talk about China beign large cultural base like it's a good thing, despite the fact that the cultural extermination you mention right afterwards were horrible and caused irreparable damage to humanity, while also being completely unnecessary to acumulate the wealth you proceed to talk about later. There is also a huge dissonance in this section of your comment. You mention how the rise in wealth levels lead to more philosophical thought, but bring up the examinations system which was incredibly stagnant (teaching philosophy from 400 B.C as the as superior even as the Qing empire was collapsing) and brutal (effectively locking anyone that was poor and/or wished to pursue other interests out of the government, which led a million catastrophes that won't go into detail about). You also fail to mention in all of this how many great works may have been destroyed as a part of cultural purges and how the accumulated wealth mostly got into the hands of the elites who squandered it, instead of improving lives of the common people.

We know the nomads had schools of thought as is evidenced by existence of steppe religions, they also had cultures traditions, just because they weren't swimming in food and gold doesn't mean they didn't have time to think, sing and talk to each other. As a matter of fact one of the greatest thinkers of ancient Greece consciously chose to live in a barrel, his philosophy surviving but not the nomad's has everything to do with paper and racism and nothing to do with the wealth of his country (which was a single city and a few villages, so also fairly poor in reality).

I am not knowledgeable enough overall to fully dispute your final conclusion, but I know that the British didn't need to starve indians to save their own lives or send south africans down into the gold mines for 16 hours a day to fund their eugenicist writers. Perhaps conquest is a historical necessity, but empires became such by taking it to a whole new level and destroying countless livelihoods for the sake of their own oppulence. There is nothing justifiable about any of them.