No guarantee that the evolution that takes care of plastics results in a more livable world for humans though (not to mention plastics that we don’t want crumbling suddenly having issues)
Yes, certainly. The value of plastics is incalculable. (Personally, if there were a plastic-eating bacteria introduced tomorrow, I would be dead within the week, rather than dead within a month or two like most people).
I don't really feel bad about plastics, mostly I feel bad about the egregious stuff -- car tires, fishing gear -- stuff that does not end up in the landfill most of all, because it cannot be segregated from the environment.
What is so special is that we are them. Until we are no longer humans, we should look out for our own. Unless you have somehow overcome self-preservation and suffering. I haven't. I never understood this "what is special about humans" argument. Obviously we should do our best to be good stewards of the environment but that shouldn't ignore our own survival.