I think the banning of disposable utensils will be hard to adopt given how big the restaurant/night market scene is in Taiwan. I doubt many people will want to carry steel straws, chopsticks, or forks. When you want to go get food, do you want to think about what food you want? Or what utensil and container you need to bring? It's far more convenient to just provide a utensil there.
I see how paper/cardboard containers would work, but how does a cardboard straw or fork work? Wooden chopsticks are mainstream but a certain thickness is required for strength, which you can't get in a straw or fork. Plus they lose strength when they get wet, so now you need to add some coating to protect them. But then that destroys recyclability which destroys the point of using such a material.
There's a post on reddit which basically sums it up - https://www.reddit.com/r/worldnews/comments/7zbjdj/taiwan_to...