Plastics are used for:
1) packaging/containers
2) art/toys
3) skin/part of tools and appliances.
4) one could define nylon/ryan/polyester/etc as plastic and say it is used for cloth/clothing.
5) misc
I count wealth not just from selling things but also from not having to pay for an additional plastic item.
Packaging: using grocery bags and trash bags.
Containers: re-fill single use
water bottles multiple times throughout the day.
Art/Toy: plastic bags into kites, and I there has been quite a few art/toys examples in post above. They are really good craft ideas esp if you have kids/grandkids one could make a culture of being creator vs just consumers.
Tools/Appliances: similar to making toys, one could make tools too. maybe melt plastic and use a 3D printer/mold to make cool stuff
Cloth/Clothing: if we define synthetic fibers as plastic, then it is possible to turn say a old pant into a short, maybe give it a refresher dye job.