I work for a government agency that spends a lot of energy on environmental policies designed to reduce pollution and address the decline in water, air and soil quality.
Is all this environmental policymaking completely pointless?
No, it's just mostly pointless. To the extent that lakes, rivers and oceans may end up a bit cleaner and usable in the longer term, and to the extent that certain species may survive the crunch, there's some kind of point to it.
Any of us who are lucky enough to survive the collapse may well want to traverse those polluted waterbodies, and eat those remaining species.