Yes, broscience exaggerated the point, but they are not far from correct.

It depends on genetics and the amount and type of PUFA consumed. The Fatty Acid Destaurase genes will dictate how bad short chain PUFA's (Seed oil's) are for a person. These people should stick to fatty fish.

https://www.sciencedirect.com/science/article/abs/pii/S00260...

Omega 6 PUFAs are more inflammatory than long chain PUFA's.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7990530/

It just so happens that most seed oils contain tremendous amounts of Short Chain Omega 6 fatty acids.

Whether or not peer-reviewed studies show an impact on health, seed oils are just kind of gross:

https://m.youtube.com/watch?v=Cfk2IXlZdbI

Compare this to making butter - shake up some cream for a little bit to separate out the buttermilk.

For balance, here’s a rebuttal to the fad that seed oils are our nemesis: https://www.the-nutrivore.com/post/a-comprehensive-rebuttal-...

There is a great book that goes into this whole topic called Deep Nutrition. Also, anecdotally, I see a lot of correlation between PUFAs and FUPAs.