Clam Shell Packaging creates waste, is hard to recycle, and is toxic from the lead and other substances. They can also be harmful and you could cut yourself if you are not careful.
Unless the can has a pull tab of some sort these can be a pain to open, especially if you don’t have a can opener handy. As well as also having a sharp top when opened.
Styrofoam is easy to make and convenient to use for many fast food restaurants. One of the main problems it causes is that it is very hard to recycle, there are not that many recycling pants around which cause most of the styrofoam to end up in landfills.
Even though the packaging looks nice, the bottles themselves are almost impossible to open, especially when wet.