The only exception is people that know the consequences on their every-day life.
This gives a signal to the market that if a lot of people does it, they should move in that direction to meet the demand.
However, this is not what it's happening, and that's because people appreciate that something is cheaper thanks to single-use plastic of because they are not so interested in single-use plastic that they are willing to do an effort to go around it.
Basically, what people reveal when in the everyday use is that they are fine with single-use plastic, and if they say otherwise is to signal some kind of virtue because they decide not to put effort into it.
Just because something is cheap and accessible doesn't mean people understand how it impacts their lives. With studies coming out routinely showing the dramatic damage microplastics are causing to our environment and even inside our own bodies, it's only a matter of time before we come to our senses and stop it.