The question sounds hyper stupid but hear me out.
We have an underwhelming volume of shit that relies on plastic. Plastic is cheap and versatile. If we replaced the vast majority of it, I presume costs for most products would creep up, and we would also shift our demand for natural resources (such as wood for paper ). Are there enough resources to sustainably replace our current volume of single use plastics? Or would we be sentencing all of our remaining forests to extinction if we did? Would products remain roughly equally affordable?
Let’s imagine we replace, overnight, all single use plastic in this hypothetical scenario with an alternative. All parcels are now mailed in paper; waxed paper if you need humidity resistance. Styrofoam pebbles are now paper shreds and cardboard clusters. No more plastic film, anywhere. No more plastic bags, only paper. No more plastic wrapping for any cookies confectionery, etc; it’s paper and thin boxes like those of cereals. Toothbrushes, pens, and a variety of miscellaneous items are now made of wood, cardboard, glass, metal, etc. The list goes on, but you get the idea.
Is this actually doable? Or is there another reason besides plastic companies not wanting to run out of business that we haven’t done this already? Why are we still using so much fucking plastic?
Zero plastic doesn’t need to be a goal. There has rarely if ever been a more versatile and useful material. Delivering food and medicine to humanity would be impossible if we all woke up tomorrow without plastic.
So it’s more a case of judicious use:
There will be many cases where “no feasible alternative exist” and that will mean “it is prohibitively costly to do it with glass and steel.” I think that is really your questions. The answer is yes, sometimes plastic is actually best.
But I’d feel much more comfortable deciding that for a given use case IF #2 actually existed. Under current conditions, there may be no reasonable use of plastic at all.