I tried paper straws a couple of times at A&W and it wasn't that bad. Granted, it was a cold drink, which could perhaps be problematic with hot drinks, but beside a texture difference, I found the paper straw to be an acceptable replacement.

They were probably coated with wax, which make them... non-recyclable.

Wax-coated paper is probably far safer to dispose by burning than plastic.

I'm pretty sure platic straws are not being recycled. Paper straws are at least more sustainable.

Sure, they will be dirty with whatever you drink too. But they are bio-degradable, compared to plastic.

I actually have a 3D printed PLA straw (nominally compostable) that I reuse (single layer so it can be cleaned/dried). Weird, not super feasible for most people, but I needed a straw and didn't have one.

They just need more wax then. Cups made from paper work perfectly well; so should straws.

The cups are typically coated in plastic, last time I checked. (This is not obvious from looking at them though).

I can't say I'm a cup expert, but I'm quite sure that paper cups (or straws) can be made waterproof if impregnated with wax.

You don't need to make them waterproof. How long do you plan to drink a soda or whatever else?

My kids are done in max 10mins and they look mostly untouched.

I left it for one hour in a hot cocoa though, and it was not intact anymore but still usable to a degree.

Let's say somebody gets served their beverage when they sit down, then neglect it until after they're doing eating. In a cold beverage, I'd want a straw to last at least an hour. I don't think that should be hard to accomplish either.