The biggest scam is the paper straw. You still need a certain plastic liner, otherwise the straw will melt down in 3 minutes from direct contact with liquid. The amount of plastic you reduce is penny-on-the-100-bucks-note comparing to the amount of plastic waste produced by industrial activities.
The only way to fix the single-use container problem is for governments to ban it. Either the customers bring their own/rent the shops' containers for take away, or drink their beverages in the shop.
Is this doable? I guess. AFAIR the EU are experimenting with laws around this. Plastic bags ban is already visible in many country, even in non-first-world countries.