This ability triggers only once
The need to not miss land drops early would leave both decks with lots of land and not that much to do with it, allowing a player with Goblin Trenches to pressure the opponent slowly, go all-in or do anything in between and usually make their choice work
Collector Boosters are possessed with rare and/or mythic rare cards guaranteed, plus traditional foils and special treatments you wont find anywhere elselike a Serialized Edgar Markov card, the first vampire of Innistrad
How can you not win when your entire board gets +5/+5 and first strike, trample, and lifelink
You could also make those 4/4 Dragons become 7/4 attackers
You can use it to destroy your own modular Creatures, but we cant help but feel like its just there to give Zabaz access to Red and White in Commander, but were here for it