There are a few reasons for this, and only one of those is that Xolatoyac, the Smiling Flood, one of the new commanders, is a massive damn Axolotl
For example, blue decks in Pauper use Thought Scour and Mental Note to power out Tolarian Terror and Cryptic Serpent, while Vintage Dredge decks use cards like Prized Amalgam and Vengevine to flood the board with creatures from the graveyard
Great Wall was there to stop that card and only that card er, rather, take away its crappy ability
The payoff is okayish, with the third chapter trigger being particularly spicy if you've got Firecat Blitz, but the cost of discarding your hand and the risk of the saga being destroyed before you get to the second chapter is too risky for me
If you assemble Tron on turn three and you dont have a Karn Liberated in hand to cast instead (which is what you really want in these matchups), then you can cast your Thoughtseize-on-a-stick and present a clock that will kill your opponent on your eighth turn
A big part of that comes from Zimone, Mystery Unraveler, who is such a terrifying commander, able to cheat giant creatures onto the board, and facedown, which will always leave your enemies second-guessing
