Trans fats are an obvious no no. Those occur naturally and in manmade products (hydrogenated fats).
But many vegetable oils (oilseed rape, peanut, sunflower, olive) etc are contaminated with aflatoxins produced by fungi that can cause liver cancer. Similarly, vegetable oils can contain Benzo(a)pyrene after you cook them.
The most healthy fats are unsaturated fats.
But we are all going to die at some point anyway so invest your health in what you love.
Regarding coconut oil, there was a bbc documentary that showed coconut oil was medium CT and so reduced LDL . Obviously too much is a bad thing but I do think it’s a good oil, not to mention the brain benefits of MCT’s