It also ignores that animals produce the manure that is used to fertilize soil to grow crops in.

We use manure because it's coming out of the gills of the animal ag industry, not because it's necessary to enrich crop soil.

Just because plastic bags are ubiquitous doesn't mean it's the only nor best way to carry items around, nor that we'd lose the ability to transport goods if they were phased out, nor that they don't come at a cost despite perceiving them as free.