Earlier quoted context omitted.
It is still better than doing nothing. It also will promote materials that are a better fit for recycling.
In the case of banning plastic bags, certain areas have seen an uptick in feces in areas because the homeless were using the bags for defecation and sanitation. The ban he had an impact, detrimental to the point where a first world nation is on track to have preventable disease outbreaks. There are cost benefit analyses that should be done prior to saying that a ban is better than nothing.
There are many other possible ways to address this problem.