The whole world is NOT affected by the “plastic mess in oceans, forests, etc”. Nobody is harmed by it. The so-called “great pacific garbage patch” is invisible. It’s made up of microscopic particles of plastic that bother nobody. Because the truth is that plastic does degrade into these tiny particles.
And the only paper bags that will be available have no handles, and cannot be relied on to get your groceries home in one piece while walking or taking the subway. The result is going to be less impulse buying, less buying from small shops, and more planned large shopping trips and shopping online. Which is going to hurt the small stores.
But the bottom line is that this is an invasion of our G-d given liberties. If we want to use plastic bags we have a RIGHT to use them, and no government has the right to prevent us. George Washington would be wondering why we haven’t yet strung up all these dictators from trees.