The point is another: we do need packaging in general, because we need to move stuff around and store them. Things we move and store have a separated lifecycle

The point is another: we do need packaging in general, because we need to move stuff around and store them. Things we move and store have a separated lifecycle respect of their packaging and packaging have a cost. Now a cotton/manila/sisal/* bag if "less pollutant" per se than a plastic one, but cost much much more to be produced and I do not know in ecological term the impact not of cotton per se but enough plantations to satisfy the demand of bags. That's is. In the relatively recent past plastics was sold as environmentally friendly because with it, coming just from a liquid pumped from underground, we can avoid cutting soooo many trees, bamboos etc and soo much energy to process them just to make packaging. Now the refrain is the opposite. Long story short the point is not "this pollute more than that" but "on scale using this pollute more than that".