Sure, its a bit odd, but its also fun to solve a deckbuilding puzzle
Given how much card draw there is, its not impossible that you get that ultimate on the turn after you play Teferi
Basically, by opening boxes on release day (or release weekend), we can take advantage of the excitement for the new cards (new demand) and the fact that the freshly opened cards haven't had time to reach the market yet (lack of supply)
While other players can stop you drawing from Esper Sentinel, more often than not, they won't want to wait an extra turn to play their spells, more or less ensuring the card at least replaces itself
it's just one that, for the most part, will result in slow, methodical turns if you start thinking about the various ways you can win
I have a group hug Princess Twilight Sparkle deck, and Ive never had anyone say no to playing with it after I explain the goal is for everyone to win the game