Here in California, most single-use plastic bags have been banned since late 2016, and in many urban and progressive localities they were banned for quite a bit longer than that. Just speaking from my own experience, I’m happy to have the ban in place. We have a big roadside litter problem in most of the state’s urban areas and their connector freeways - especially in the San Francisco Bay Area - and single-use plastic bags used to be a major component of that. The ban eliminated new sources for that component overnight. Now if only all the rest of the garbage could be as handily managed!
But anyway, no longer seeing plastic bags blowing across the freeway or fluttering in the breeze from the snag of a tree or fence, has significantly improved my mood while driving. I’m all for the ban. I offer my regrets over the overall-carbon-footprint issue, but I’ll admit I prefer seeing cleaner streets, creeks, and shorelines, than subtle fractional incremental effects on climate that I can’t discern from all the rest.