Just as a one-off, because I have an answer to this.
I am a history buff by no means. In fact I'd say I suck at retaining information you tell me about "what happened" and certainly of producing a reasoned opinion from a set of biased records. But a history buff I know explained how a certain point in history, China was able to "catch up" to the West because, to put it his way, "They didn't need to reinvent all the technology." It was already there. And I expanded on that to say, "... okay, but what precisely is the economic gain of not needing to invent the technology?" And the answer is that no one has to do any experimentation or attempt any capital investment projects that you don't know are going to work, just for the sake of learning. No one has to be set aside to pay the toll of experimentation and exploration. You can use your population to "cut the R&D sector to 0" and boom from almost pure capital intensification.
To recreate -that- effect, in that way, the game needs to have technology diffusion , and it needs to have an amount of citizen assignments , at a percentage scale instead of a maximum science slots, go to concentrated science gain. In this case, the China player took all citizens out of this second one, just to enjoy the technology that was already at hand - building infrastructure in the cities.
Let me add to this because, as a few of you might have guessed by now, I am a history buff and then some.
China's historical technology rush to catch up with Europe started much earlier than most realize, and started from a solid technology base that was already there. China developed all the early gunpowder and metal working technologies well before anyone else (cast bronze hundreds of years before Europe, cast iron almost 1000 years earlier, high-temperature coal-fired furnaces at least 500 years earlier, simple cannon and muskets several hundreds of years earlier, etc) BUT China's technological progress was not subject to any outside pressure or Need - China's neighbors adopted Chinese technology, but China adopted very little from the outside and had no competitive reason to 'push' technological progress. Any such pushing came from the whim of the government/emperor and lacking that, China reached a comfortable level of tech (wheel-barrows, fine porcelain, fine metal-work, a high level of food production) and stopped. The Europeans in the 15th - 16th centuries, basically lapped her.
China very quickly caught up by copying matchlock mechanisms from Europe and adopting volley fire techniques originally used with crossbows (also several hundred years before Europe developed the same techniques), so that Chinese, Japanese and Korean small arms technology and techniques quickly matched European.
Cannon were harder, because the great wall-smashing Bombards of Europe were almost useless in East Asia: walls were made largely or rammed earth or solid earth dozens of feet thick, and the large solid shot simply did not do any damage to them the way they could smash stone curtain walls in European fortifications. So here the technological advance or 'catch up' was slowed enormously by a lack of Immediate Need. That need appeared when Portuguese and other foreign ships showed up with heavy shipboard cannon and sank everything Chinese in sight in the late 16th century. The Need was satisfied when a bunch of heavy cannon were salvaged from the British ship
HMS Unicorn that ran aground and sank in a Chinese coastal river, allowing the Chinese to 'reverse-engineer' the guns and produce their own - stolen technology, if you will, but helped by the fact that the guns were cast iron, a technology that China had originated over 1500 years earlier!
The next 'catch up' was harder: when European steam-driven gun boats began appearing in Chinese waters in the mid-19th century, since a steam engine required much more complex and precise metallurgical technology than China possessed. With French engineering help and Chinese engineers trained in American and European universities, the Chinese government managed to build a shipyard in Fuzhou that by 1873 was building Chinese steam gunboats with modern guns that a British naval officer described as "“better than . . . British vessels of the same type"!
So, IMHO, to include Technological Diffusion in the game without making it a Fantasy mechanic, three things have to also have to be included:
1. Need. This should be one of the most basic driving forces for the Tech Tree (or Bush, or Creeper Vine, or whatever form technological change takes in Civ VII). People will not bother researching and adopting technology that they don't need. There will be no boat-building Tech in the desert. There will be no development of Wheel technology if you have no draft animals to pull the wheeled vehicles (Fun Fact: the Aztecs and Incas were perfectly familiar with the Wheel - they both had wheeled toys for their kids. But they also had no draft animals to pull larger wheeled vehicles, so never developed spoked wheels, harness, or any of the other tech that goes with 'real' wheeled vehicles). If you need it enough - like your opponent appears with steam warships to your wind-driven Junks - you will beg, borrow, or steal the Technology as fast as possible.
2. Each Technology has to have a Diffusion Score indicating how easy it is to copy and adopt. See a solid wheel, it's not hard to see how to use it and copy it. See a Steam Engine, it's going to require a lot more Prior Knowledge to reproduce it no matter how much you need it. A large component of the Diffusion Score for your Civ will include how much related Prior Technology you already have. China had very little problem adopting superior European metallurgical products like matchlock muskets and cast iron ship cannon, because she had already been making intricate metal products and cast iron objects for centuries. No American native Civilization ever managed to develop its own iron or steel technologies, because only a few of them had any metal-working/smelting technologies at all.
3. Individuals as Diffusers. Civ's unique strength has always been its personalization of History. Named leaders, governors, Great People, etc. It's been a standard part of Civ throughout the series. A lot of Technological Diffusion and Knowledge Diffusion throughout history hinged on individuals, many of them named, so that this Civ Meme can and should be included in Civ VII. Chinese development of Steam Engines and modern (Industrial Era) naval architecture sprang from a single Chinese engineer (Yung Wing) trained at Yale University in the USA, who bought a complete machine shop (with Chinese government money) in New England and brought it and his knowledge of how to use it back to China. This shop became the nucleus of China's first modern shipyard and Arsenal producing modern ships and artillery. An 'individualized' Technology Diffusion/Spread mechanic would fit right in with Civ's individualization of game mechanics in general and advance the spread of Technology to avoid the ridiculous imbalances that occur in the late game now.