This might not seem like a lot, but on a six-sided dice the increase of just one is a lot more impactful than on a 20-sided dice
Josh Lee Kwai highlighted a five-color Nekusar the Mindrazer deck very early into The Command Zone podcast run, and I discussed aspirations of building around The Gitrog Monster in a four-color deck in the last few months
Boros Aggro where this is an on-curve option to removal in the creature that can mix it up and go wide with copies too
It means that under this player control all phase-out permanents and phase-in permanents with phasing do not change their status
This means that you can expect draft decks to be slightly better, more powerful, faster, and (most importantly) more focused than in Sealed Deck
Paying four to exile a Creature is steep, but paying two at instant speed and giving an opponent a draw is quite a bit better