You can make paleo type glue from birch sap or pine and spruce saps. Takes some work, is not pretty and clean, but worked on Viking ships, Celtic, too I think. I did it as a kid, but don't remember much. I think my bros were making primitive lances and arrows and needed more than buckskin to secure the points. They tapped the trees, while I tended the fire to cook down the sap.
You can also hold stuff together with pegs if you don't want to use nails or brads or screws.
My view on plastics and recycling in general is evolving. The fact that we are here on this board is indicative that we are less significant consumers of plastics than many others around us. Really. Disheartening.
My sister uses cleansers with those plastic micro beads that are turning up in volume in the Pacific Gyre. (But she does use her own shopping bags.) Also does a lot of take-out, and lot of single portion sized stuff at the grocery store. Reuse of many plastic containers is good, but my Brother in law is washing out his plastic sandwich bags, which my sister secretly throws away. They also insist on putting stuff in the recycling bins that shouldn't be there. Detergent bottles, caps on bottles, pizza boxes, Styrofoam, plastic wrappers, and those air pillow package fillers, etc. All theoretically recyclable, but not in their area. I've tried education with them but they are resistant. To each his own.
Back in the 1920s, my mom and her sisters would carefully peel the thin foil from the thin waxed paper that wrapped their occasional sweet treat. Those shreds of foil would be recycled in a huge barrel, that a man in a horse drawn wagon would pick up every few years.
Reuse of current household plastics: I do keep the random plastic bag and use it for household trash or for wrapping very wet garbage, or for covering shoes when needing to cross puddles. I also will line the potting surface for a short time to keep the inevitable slop over off of the wood. And use them for transporting plants in my car.
Measuring medicine doses in about 30 oz. cups, I'll reuse my own for sorting stuff or isolating stuff like weird seed collections. (From woods walks, perhaps) Also use them for testing seed viability. I love the larger plastic domes from take out that can be a cloche for seedlings. They also can be vented a bit more to make them somewhat a deterrent to squirrels or birds pecking at seedlings. I'll peg them to the ground with a random twig.
Plastic forks or other utensils have also been used as spikey squirrel deterrents, as plant name stakes, as dibbles, and with my other interests.
Plastic jugs I've used for potting, for scooping, for washing, for natural material collecting, for funnels, for paint or chemical mixing, and some for squirrel baffles. Unfortunately, I don't actually use enough plastic jugs for the uses I have for them.
Very seriously, it's rare for me to even throw away a plastic kitty litter pan. Once I determine it's too stinky/stained/scratched up, I wash it and bleach it and toss it outside in work area for whatever use I find. With all that sun and rain, it no longer smells like kitty litter and is a practical size for mixing small batches of concrete or soil mixes, or collecting various items like rocks and shells that are in the plant beds. My cats don't even recognize it years later.
Oh, and bird seed and other stuff is sometimes coming in these woven plastic bags. That's recyclable #6 which has lots of interesting applications as a shrink plastic, but is also useful for a semipermeable tarp/windscreen/sun shade for temporary application.
Black plastic plant pots will usually be picked up by someone cruising by if you set them out on the curb. They are not supposed to be included with our recycling, no matter what my sister tells you.
When dumpster diver/metal recyclers pick up largish appliances, they can use a lot of the stuff in some way, but generally plastic housing is just trash. These are people who will separate the ferrous bolts from the aluminum handle and peel the copper from the coils, and use acid to extract the precious metals, but there simply is no really practical use for the excess of plastic. Some of it could technically be recycled, but city services typically don't want the housing from microwaves or the spin column from a washer when you have these in quantity. One here and there is okay.
Speaking of DD, I'm on the lookout for another washer drum with all the perforations so I can build a small composter.