All of those problems can be solved pretty easy with nanomachines, actually. They can remove pollutants from water. Repair the damages done to biosphere and many more.

https://scitechdaily.com/scientists-develop-nanomachines-that-can-penetrate-and-kill-cancer-cells/

Any kind of collapse is not an option for the society. Current modern society requires integrated, large systems to keep functioning to keep people alive. Any critical product or service stopping due to any kind of collapse would kill billions. Even the lack of cholera, dysentery medicines would be enough to do that actually.