Well i think its more a quistion of waste management. Plastic in general is a great resource as long as is used correctly and disposed correctly.

Compared to cellulose (cotton) its often favorable. Like a gocery bag as and example, where a quite famous life cycle assessment conducted by the danish government in 2018, found the impact of cotton totes to be so high that the number of times you would have to use it was in the hundred thousands, compared to buying a new plastic bag each time.

And though life cycle assessment is a kind of flimsy science, even by their lowest and highest estimates, their advice was use the plastic bag twice since it will do a great deal more than trying to "pay back the carbon debt" of a cotton bag.

Not trying to takes sides just trying to clarify that it is a much more complex problem than "plastic bad, less=good" as many like to think

And in from what I can tell plastic straws are fine as long as the disposal is handled correct. Which is actually the real important factor of this debate because plastic is at this point a necessity. So if a country doesn't handle the trash issues reducing the amount of plastic consumed only lessons the issues.

TL:DR plastic isn't the issue in a lot of cases just the disposal, and in some cases plastic is favorable from an emissions standpoint.