When I considered these statistics and outcomes, here's what me and my family started using...
It's a traditional style Rantang container. Also known as Tiffin or Dabba in India and Bangladesh.
I was sick of getting styrofoam/polystyrene containers and plastic bags when I ordered takeaway food. Not only is styrofoam the worst kind of plastic to eat from - it's the worst kid of plastic to BURN! All plastic burning produces dioxins and will eventually give you lung disease or cancer, but styrofoam will kill you so much faster.
I bought these 3 enamel stacking containers from Delta Dewata Supermarket for 65k (about $5USD), and now when I get Nasi Bungkus from a warung or cafe - I get it served in these containers.
And travelers - when you leave Bali - hand the containers on to someone else and explain why - they will last for a long time!