3. Australia - Outback Station [30]
7. Cree - Mekewap [32-3=29] I don't know why this one is leading. I think the Kampung does a better job because they both really do the same thing, but kampungs at least allow you to turn weak coastal tiles into something great, freeing the land tiles for other use. Also, pop is good, but it's better to go wide. A wide empire with low pop but unique districts like the Lavra, Acropolis, or Seowon will be more powerful than a tall civ with the production/housing/food/gold improvements. Districts > Improvements in Civ 6 as a General rule. The Outback Station also is overrated for similar reasons.
8. Dutch - Polder [10]
13. Germany - Hansa [19]
14. Greece - Acropolis [19]
16. Indonesia - Kampung [32]
20. Korea - Seowon [17+1=18] This is an amazing source of steady science, and should at least be in the top 3. Seowons win science victories. Lavras win religious ones. Acropolis win cultural ones. I don't know why districts aren't leading; they're just so powerful and indispensable.
26. Persia - Pairidaeza [26]
29. Russia - Lavra [25]