Did you confuse saturated and unsaturated fat? Saturated fat isn't bad for you and unsaturated fats have some serious issues in how your body uses them. This comment feels like it was posted by someone in 1997
Show me evidence that replacing unsaturated fat with saturated fat improves human health outcomes. If you can't, then I have to ask you how your epistemology works if you don't need a mountain of evidence to surmount the scientific consensus.
You'll find that this "debate" cashes out into two sides: one side points to the balance of scientific literature on human health outcomes, and the other side hand-waves over mechanistic speculation.
For example, the latter side likes to blame seed oils when they actually improve human health outcomes: https://www.the-nutrivore.com/post/a-comprehensive-rebuttal-...
However, it is clear that dietary fat does not just directly go into your circulatory system.
Saturated fat is only solid at room temperature, not biological temperature. Put a tablespoon of coconut oil or butter in your mouth and see how it melts. More importantly, our body makes saturated fat. It's part of every cell's membrane. The science on which fats are good for us is still being debated, but I think the overall consensus so far is somewhat as follows: animal fats have more toxins (such as dioxins), and tend to come with cholesterol; non-animal fats are cleaner (whether saturated coconut oil or unsaturated types). Consuming too much fat blunts insulin sensitivity, but consuming too many carbs does likewise but in different ways. Carbs seem to be the bigger villain, but trans fats and low quality [rancid] oils are bad too. Having a good omega-3:6 ratio is anti-inflammatory and good for us. Eat lots of non-starchy vegetables, plenty of high quality protein, and reduce sugar consumption.
Data has been coming out over the past decade on how all the unsaturated fat touted as healthy is actually harmful, as it disrupts our hormone balance and increases inflammation. On the other hand, saturated fats are good for hormone balance, but I definitely wouldn't go out of my way to eat bacon or other high-toxin saturated fat. I'll just stick to the basics as stated in the previous paragraph.
The idea that saturated fats are better than unsaturated fats is a small minority opinion. It's all the rage with wellness influencer types, but it is currently supported by far less evidence than the consensus.