It takes a lot of mana to make the removal side work, but if you manage to get delirium, it doesnt really matter as it doubles the damage of your burn spells, as well as pingers like Thermo-Alchemist
But lets be real, its price is also high because running a big dragon who commands a big dragon army is just pretty great
Note that the creature is hitting their controller, so you can get some triggers
For one thing, life advantage doesnt translate well into other aspects of the game, such as having more cards in hand than your opponent or having better creatures on the battlefield
After all, there can be only one winner to rule them all
With six or seven creatures in the yard, its strictly better and doesnt get worse if creatures are removed/exiled from the graveyard after its in play