Win conditions shouldnt outright win you the game, no. They should give you the edge.
The quests arent even win conditions at this point either, they are all otk combo decks.
They require no risk to gameplay. You just play mage like you normally do and you get gifted free +3 spell damage. Theres no risk and 300% reward
Dont even know why you are trying to defend these quests lol. They are very clearly outright broken. They have completed ruined the game because you cant win against them unless you manage to beat them to the punch. So you either play these otk quests or extreme aggro. That is the only option. You cant play mid range, you cant play control, you cant play niche off meta decks.
This is the worst most stale meta this game has ever been in that ive played. Its quest or lose. And whats worse is anyone can do it because they require little to no strategy or thought. Theyre dumb and need nerfing. My suggestions reign them in while keeping them as win conditions.