Arable land now affects agriculture efficiency, more land means more opportunities for field rotation and sustainable farming
Propaganda maintenance now scales with population, larger empires need more effort to maintain state messaging
Soil fertility now provides even more food output from agriculture
Agriculture decays slower and grows higher before hitting the peasant population cap
Education policies now cost less Political Power to maintain
AI improvements: smarter resource management, better food production (invests in agriculture, fishing, hunting, foraging), no longer cuts agriculture support when starving, implements new tax systems (tithes, minting, trade policies), researches late-game economic nodes (stock exchange, mercantilism, laissez-faire), maintains more diverse armies instead of over-specializing in a single unit type, and now reduces officer corps spending when running low on wealth
Late-game performance improvements for AI civilizations (smarter rule caching) and rendering