Ashiok offers us a whopping 20 cards of self-mill for just three mana, AND simultaneously applies two brutal limitations to opposing decks
Put another way, for every two copies of Teferi, Who Slows the Sunset, theres three copies of Arlinn, the Packs Hope
You can play both lands and spells, but you can only cast spells
For perspective, the difference between the cheapest Standard deck in the meta and the cheapest Legacy deck in the meta is roughly $2,000
This years printing of Aminatou, the Fateshifter took the core cards cards like Future Sight and Oracles Vault and added white and black, so I can do fun things like survive Duskmantle Seer longer than everybody else, get whatever I want out of Druidic Satchel, and break the symmetry of Zurs Weirding (since I dont need to draw cards)