The real prize when playing Jace is the quick ultimate ability to make two copies of the legendary planeswalker that you can activate immediately to take over the battlefield
Controlling a player doesn't allow you to look at that player's sideboard
Finally, the deck aims to put tons of cards into your graveyard, and then take advantage of this (for example with Izoni, Thousand-Eyed, Golgari Grave-Troll, Jarad, Golgari Litch Lord, etc)
Animating your expensive artifacts and enchantments is a fantastic payoff
Of course, the potential of Silvergill Adept is somewhat limited by the fact that you need to play it in a Merfolk deck to cast it for two mana, and Naban isn't a Merfolk, but as the only straightforward "draw a card" Wizard in Standard, it still might be worth the effort if we can find a build to support the mixed tribal synergies
Commander falls a bit in between these types, as it can be played both casually and competitively, with the former often being called EDH (Elder Dragon Highlander) and the latter cEDH