I've seen several studies that dispute the efficacy of reusable plastic items (bags, cups, etc). The energy costs of producing the "sturdy" alternative are often high enough to offset the gain in reuse.
IIRC, one study showed that reusing the single-use grocery bag one time (as a trash bin liner) was enough to put it back ahead of the typical $1 reusable bags available at the check-out counter at most grocers.
Since reusable bags have so little mass, I am not so concerned about the energy use to produce. More about the amount of bags and micro-plastics that escape into the environment.
That's fair. And I'm definitely in favor of doing whatever's best for the environment. Just pointing out that it's not as simple as "reusable is better" - depending on the set of metrics being measured, it might not be.
I never claimed they're filling up landfills, that was somebody else. I was just providing some more context, which as you note, indicates it's not as simple as "reusable good, one-use bad".
