there is so much misinformation about what is and what is not biodegradable

• A lot of organic things are not composted but they could be, they just need much longer time. The chicken bones you mentioned are an example. But also like wood or oak leaves are compostable but people think they weren't
• A lot of synthetic things are thrown in composts that do not biodegrade. Many teabags are from synthetic material. Almost all clothes, even when they say 100% cotton or wool are sewn with sythetic thread or dyed synthetically or contain superwash-polymers. All kinds of lacquer (esp. on wood) or colors are not biodegradable
• If you care about this, you generally cannot share composting facilities with more than 2 families max. Someone always fucks up