Playing devil’s advocate here, there’s a couple issues with that. First, an empty spot in the pack means it will crush more easily in someone’s pocket, during shipping, etc. Second, like you mentioned, those things are smelly garbage once they’ve been used. A lot of smokers aren’t going to make the rest of their pack taste and smell like that, or carry that smell with them all day long. Also, it doesn’t address the issue that these single use, disposable things are made with plastic in the first place.