Lots of folks have been discussing, playing with (exploiting?), and researching [ASMR](https://en.wikipedia.org/wiki/Autonomous_sensory_meridian_re...) over the last few years. However, I've yet to see any discussion about the possibility of a connection between ASMR and [misophonia](https://en.wikipedia.org/wiki/Misophonia). I experience both (your comment caused me to shudder) and have a hunch that they form a duality or, if the distinction isn't that clear, are related.
I don't know if there are effective, inexpensive substitutes for those uses.
Using styrofoam in helmets, car bumpers and refrigerators is a completely legitimate use case as it solves more problems than it creates, but using styrofoam in cups is just such a complete waste that only gives someone a tiny bit of convenience.
For others, like food containers, it's almost purely for cost reasons when other solutions exist.