In Civ 6, I feel that science progression needs to be restructured. Historically, civilizations exchanged ideas quite rapidly. Once one civilization made one innovation, neighboring civilizations followed after. Ideas would spread across the world usually until they met a geographical barrier like the Sahara Desert, Atlantic Ocean, or the Himalayas. The more closely a civilization was connected with other civilizations, the quicker the flow of ideas. This empowered civilizations that engaged with the rest of the world. Isolationism usually meant a much slower progression in technological innovations and science among other things. In civ 6, that's not the case. Every civilization more or less has to reinvent the wheel for every single tech. It doesn't matter if you're the Netherlands on a TSL earth map, and each of your neighbors (France, England, and Germany) have each discovered a tech. You still have to research the whole thing yourself as if you were completely oblivious to it, despite shared borders, trade routes, and a lack of major geographical barriers. For this reason, I think that it would make more sense to replace the eureka system with a system of boosts based on one's connections with civilizations that have already researched a tech. Important variables including geographical distance, trade routes, cultural similarities/differences, and geographical barriers. Isolationism is too advantageous in civ. Historically it was usually the other way around.