Polymer fumes do seem to be a thing at high temperatures apparently https://www.healthline.com/nutrition/nonstick-cookware-safet... https://en.wikipedia.org/wiki/Polymer_fume_fever
In terms of health, I'm not sure either but you should never use non-stick pans if you have pet birds. As I understand it the way their breathing and lungs work makes it deadly for them. Aside from that as long as it's not proven safe I don't feel like taking unnecessary risks when multiple safe materials are available. Manufacturers claiming their product is safe when it isn't has probably been a thing before the first factory and will still be a thing after I'm gone.
Not really across the research but my suspicion would be that if there are issues associated with non-stick, it’s likely to be PFAS driven.
There was a good discussion about the evidence on PFAS that I watched a while back, but I cannot find it for the life of me, sorry.
Whether non-stick coating peels off when cooking or when washing is an open question, but chances of it being just the latter are slim to none.
A better option is copper-inlayed steel pans, something like Falk. They aren't hard to master and they last for decades and have superior heat distribution profile.