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?
You absolutely can open the top of one more.
I can use my tooth and take the top right off and make cups out of cans. Do it all the time camping.
They work fine except for the sharp edge because it’s just like being opened with a can opener.
You can crush a disposable paper cup easier then a soda can with the top taken off