PFAS materials (teflon, high temperature o-rings, refrigeration fluids, fire-fighting foams, anti-cancer drugs and other medicines, etc.) encompass such a broad range of chemistries (anything with the fluorine atom attached to carbon) that have many many orders of magnitude differences in half-life.
It’s analogous to labeling anything radioactive (bananas) as a “forever chemical” because some radioactive nuclear waste does have >10k year half-lives.
The nice thing about PFAS compared to nuclear though is that even the ‘forever’ versions that have really long half-lives can be easily catalyzed to break down using the right materials/temperature/pressure.
People are looking for catalysis processes to get rid of nuclear waste using atto-second lasers: https://bigthink.com/the-present/laser-nuclear-waste/ (Would be amazing if it works)
Also, fluorine incorporation in water is starting to be reconsidered by some in the medical community (greatest volume of human fluorine consumption by far): https://pubmed.ncbi.nlm.nih.gov/8169995/