There isn't anything here to suggest countries are bargaining in bad faith, they seem to be pretty up front about what they want and why they want it. And I don't see why there is a presupposition that an anti-plastic treaty is a good idea. Plastic is clearly of enormous value to society, and the linked treaty draft looks a bit wishy-washy.
> Parties shall cooperate in order to prevent disputes and shall seek to settle any dispute between them concerning the interpretation or application of this Convention through negotiation or other peaceful means of their own choice.
The section on settling disputes looks like gainful employment for a veritable office of lawyers with too much free time. I see that this is all backed by the threat of rendering a report if parties can't find common ground. That is so soft that I expect anyone operating in bad faith would just sign on to the treaty then ignore it.