There's little evidence surrounding seed oils - https://dynomight.net/seed-oil/

I expect that, to the extent there's a problem, it's that they are an additive to most packaged/ultra-processed food products which can be non-satiating, and therefore boosts overall consumption of fats and calories. Sugar of course is another component.

id recommend you look into the omega 6 to omega 3 ratio , the tldr is that the ratio of omega 6 to 3 is way out of balance in the modern western diet , from my viewpoint this has been spurred on by oils such as soy and canola which are very high in omega 6