It is adequate.
It performs it’s function.

No need for extreme consumerism & garbage production.

It’s biodegradable, renewable, and only needs to get from the manufacturer to your cabinet, where it can be replaced with heartier permanent storage.

And it also needs to leave everything inside my backpack coated in a thin layer of flour.

What I don’t get is why they put it in a single two-layer paper bag instead of two single-layer paper bags, which would clearly be more effective.

Why didn’t you wrap it with another bag, or your reused plastic one? This seems like a non-issue user error.