Generally speaking, are defense passes useful?
Hypothetically speaking, let's say I have a Smeargle with the moveset, "Baton Pass," "Spore," "Tail Glow," and "Cotton Guard," is it worth maxing out +6 on defense and passing it to a sweeper when an adverse Pokémon can destroy (let's say, a critical or a super effective move) the aforementioned sweeper in question?
Once again, I'm just engaging in hypothesis. I just want a stalwart perspective on this.