> I don't know exactly

You sum up a fundamental problem of the world so well - you don't know, but you damn well wont let that stop you from formulating a strong opinion about it!

The best alternatives to plastic cutlery, cups and plates are reusable items. Hopefully the benefit of reusable vs disposable from an environmental perspective is obvious to you. When that is not an option, then bamboo, wood, and numerous other plant based items are much, much better than plastic. Depending on the source, they mostly have lower embodied energy, and more importantly they are able to easily undergo aerobic digestion to create a full carbon cycle. Even in a sealed landfill where oxygen is not present, they can be used in a waste to energy cycle without incineration. All plastics - all of them, including polyethylene and polypropylene which are most commonly used for these items, are endocrine disruptors. They are wreaking havoc on every biological organism on our planet, impacting reproduction in vital ways. Marks my words that plastics will be seen in twenty years as coal and fossil fuels are seen now. This is an existential threat to life as currently evolved to the same order as climate change. If our forbears had been using materials in this way, our world would be unrecognizable compared to what we see now.