This may be a stupid idea, but to my knowledge metals is are some of the best materials when it comes to being easily recyclable.
Ignoring the cost and reusability, wouldn’t recyclable disposable cups made of metal be a better deal than the largely incinerated plastic cups?
A few years ago there was this effort to abandon disposable containers entirely, so you were encouraged to carry a durable reusable container instead. Whatever happened to that?
I don’t think anyone who likes fast food liked reusable containers. Although my girlfriend always carries her water bottle everywhere.