Plastic packaging protects food from moisture and dirt. If you make the packaging out of a water-soluble material and then eat it, surely that's almost completely useless? Like, now you need some kind of additional outer wrapper to stop your edible packaging from getting contaminated.
The article mentions muffin liners as an alternative use case, but those are usually made of thin paper and are already compostable.
The article mentions muffin liners as an alternative use case, but those are usually made of thin paper and are already compostable.