I once had a player that wanted a Decanter of Endless Water just to waterboard people 😳
Tearing the bag from the inside seems like an easier said than done proposition.
Not if they have a blade. Sticking anything sharp inside the bag tears it.
Also, I would much rather suffocate over 10 minutes(which would suck horribly) than live out the rest of my natural life floating alone in the astral plane.
Do things inside float? Wouldn’t that make them unreachable if they float away from the opening?
And that’s only if they recognize what’s going on. If you’re just minding your business and suddenly it’s dark and hard to breathe, there are a bunch of monsters, spells, and magical phenomena that are possible culprits.
I’m still going to wildly swing my scimitar in the dark