Making Villagers and Minecarts More Rewarding

Librarian Trading and Tool Progression
Master-level Librarians will be guaranteed to sell an enchanted book at its second-highest level (maximum level - 1) for 42 emeralds. A new item, "Ancient Wisdom," found in Ancient City chests, can be used on a Librarian to upgrade their traded enchanted book to the maximum level.

Using "Ancient Wisdom" on any villager also applies a discount to their trades, equal in value to curing a zombie villager. By combining the discounts from curing, "Ancient Wisdom," and repeated trading, players can eventually buy enchanted books for a single emerald.

Additionally, to better differentiate Netherite from Diamond, a Netherite Pickaxe with Efficiency V and the Haste effect should mine deepslate in 0.05 seconds, down from 0.1 seconds.

Minecart Transportation Overhaul
To make minecarts a more effective means of transporting villagers between biomes:

Furnace Minecart: Allow fuel to be stacked in its UI and increase its speed to be just slightly slower than a minecart boosted by a powered rail.

Minecart Linking: Enable minecarts to be linked together to form trains for smoother mass transport.

Directional Rail: Introduce a new rail that stops a furnace minecart when unpowered. When it receives a Redstone signal, it sends the furnace minecart moving in a specific direction.

Villager AI: Villagers should be changed to actively seek out and board nearby empty minecarts, making them significantly easier to transport.