Is that really your argument? Will my BBS turn off throughout the course of the match? This comment is irrelevant.
Assuming I use my 5/5s to hit your 7/7s. When I’m Abyssian, the faction with the most removals in the game. And have you seen the old Variax decks? They have ways to generate Wraithlings besides their BBS. I didn’t want to list all cards that generate Wraithlings but I will:
Inkling Surge (1 Mana, 1 Wraithling)
Gloom Chaser (2 mana, 1 Wraithling)
Shadow Stalk (2 mana, average 2-3 Wraithlings)
Wraithling Swarm (3 mana, 3 Wraithlings)
Bloodtide Priestess (4 mana, average 2-3 Wraithlings)
Dark Transformation (5 mana, 1 Wraithling)
Necrotic Sphere (6 mana, average 2-3 Wraithling)
Vorpal Reaver (6 maan, 6 Wraithlings)
Anything that generates Wraithlings immediatly and costs 6 mana or less you can use
to combo for more 5/5s. That beats Endless Hunt easily. Not to mention Cyptographer and Bloodbound Mentor, letting you get 2 more 5/5s.