While the banned list in Modern is long compared to that of most formats, it's not that long, and the number of cards that could potentially be unbanned and would also be expensive and hyped enough to sell a Masters set is very small (it actually might just be Jace, the Mind Sculptor)
Using a few reanimation effects also enables you to get back either the creatures sacrificed to Yawgmoths first abilities or discarded to activate his second
[c]Yorion, Sky Nomad[/c] sees competitive play in a multitude of formats, in part due to its more forgiving deckbuilding restriction
There are also several categories of events which dont use the stack, and thus do not create a window for any player to react before their effect takes place
The design team (Bill Rose, Joel Mick, Charlie Catino, Don Felice, Elliot Siegel, and Howard Kahlenberg) expressed interest in exploring effects that were too small to go on a spell
It is not immediately clear to me if you'd prefer to get a land or a treasure, but it certainly provides card advantage