For a big chunk of the industrial age we've operated on the assumption that the global environment is big enough and capable enough to just eat or neutralize just about anything we dump into it. I think there is utility in defining a category of human-produced things that we have been able to determine the global environment can't eat or neutralize, and also that cause harm when people are exposed to them.
You could give this category a lot of potential names, but "forever chemicals" conveys the idea pretty effectively IMO.
https://en.wikipedia.org/wiki/Persistent_organic_pollutant
into google, gets you this link:
https://en.wikipedia.org/wiki/Per-_and_polyfluoroalkyl_subst...
"forever chemical" in either Google or DDG gives a lot of good links explaining what they are.
Disregarding any nomenclature, in just focusing on the terminology in isolation, water could be considered a forever chemical. This is an example of why use of the term "forever chemical" comes off as a scare tactic or disingenuous.
Of course, for dying media institutions, PFAS can't just be a pollutant. It has to be literally forever!