[TeMPOraL]

Because:

- there are very many plastics with different properties, and - AFAIK - not all of them can be replaced with plant matter

- replacing all plastics with plants will likely compete with agriculture for land use

- if you just went and banned plastics, we'd have to use things like glass, metals and woods instead; not sure how the manufacturing footprint compares between metals and plastics, but just consider that if every plastic item you have around you was made from steel instead, how much heavier everything would be, and how it would impact energy requirements to move those things around

Plastics are pretty awesome materials.