Courser of Kruphix, Heros Downfall, and Languish have forced the older versions of the deck down a path to only need white double white for Elspeth, Suns Champion too far down the line for a dedicated manabase
not every card from the Commander Deck will make it to Arena, but every legendary creature of the Commander Deck will head there, and various bundles come with Mythic Turtles, special sleeves, and more
It compresses time
Merging equipment with a planeswalker delivers excellent storytelling while it provides a unique playstyle that encourages players to run lots of proliferate effects and build up to an explosive finish
Emerald/Steel is very handy against that particular deck, and most matches Ive played against it are relatively easy wins
Oh, and it also happens to mobilize 2