If that extra card is a Battle MasteryBattle Mastery to go with the Ancestral MaskAncestral Mask you just drew and the Nylea's ColossusNylea's Colossus you could also bring back, it may be the difference between ending someone or letting them live just long enough on to kill you on the crackback
This also works in a more late-game control deck, draining your opponents Lore and subtly slowing down their game plan
From there, a Walking Ballista can win the game, and this combo can be set realistically on turn 3 if you have a good hand or with the help of some creature tutors
And members often have rare and hard-to-find cards available
When Dominaria United came around, there was a lot of tie-in with Legends thanks to the insertion of cards from that set into collector booster packs, and Wizards took this a step further by reimagining several older Legends legendary creatures
Pressure goes hand-in-hand with card draw