This is certainly a valid topic. The pots are made from common thermoplastics, and should be easily recycled with plastic bottles, especially since they are likely to be clean; an easily-peeled label helps. But recycling authorities (here, anyway) are often conservative and say 'nothing but bottles'.
In the context of the amount of plastic we are still using, I suspect film containers are a small problem. I have a box for empty Adox pots; I'm not the most active film user in the world; I may have dozens of them; certainly not hundreds. It would be great if there were a channel to return them to Adox, but I imagine it would amount to a lot of effort for not much actual plastic; I buy my Adox film by internet/mail; if I were buying it in a physical store you might imagine a bin by the counter to return pots, which could be picked up now and then by a delivery guy; but it's harder to justify mailing my few empties to Germany.
In any case, for a product that really needs to be and look pristine, even slightly-worn containers wouldn't be welcome back.
If the beer- and winemakers won't reuse bottles, we can't expect Adox to.
I have reused Adox pots for (i) carrying film of other brands that came in a multi-pack box; I wouldn't usually take a whole box of five out with me. Also (ii) carrying exposed films of any brand; and (iii) containing rolls that I have taken out of their packaging and cut down to 127 size. I have also used them for non-photo purposes: (iv) containing drill bits etc., and (v) containing a small amount of my own tea when visiting people whose choice of tea I don't trust (I drink weak tea; for coffee I need a bigger container). When I worked at a university, a lot of people had stuff they kept in little reused containers, and if I'd left my empty Adox pots in the canteen with a 'help yourself' sign they'd have gone to a good home.
I think (polystyrene?) spools are a bigger problem, because they aren't much use for anything.
I have arrived for a visit wearing contact lenses but without the little case they live in overnight, and used a 35mm film-pot as an emergency measure. I don't use any bodily accessory that needs a pot of 120 size; YMMV.