I like that one and it has good references. I could find more (Crisco and trans fats... duh) but I mean come on...

Seed oils like canola oil are manufactured and did not exist before 1900. They're totally unnatural and heavily manufactured with solvents, preservatives, high heats, deadorizers, coloring. Seed oils go rancid so fast without chemical processing and preservatives before they're bottled.

Do you want to cook with stable saturated fats in ghee that has been used for generations after generations - Or manufactured seed oil, first sold to the public as Crisco by P&G? Seed oils do not occur in nature, they are manufactured. Do you want to shove it down your gut until good enough studies prove it's safe or unsafe? Not me!

Vegetable oils. Good history here: https://www.youtube.com/watch?v=4Uqj35nHB0g&t=749s This doctor looks into numerous studies in this lecture, but fats and seed oils are covered from 749s as linked and the next ~25 minutes. Its part 1 of 3 lectures. Highly recommend

There are also some molecular pathways that might be triggered by substances in plant oils but there's not much systemic research into this yet.

But I think it's all plausible. There's really no harm in restricting yourself to just olive oil out of all extracted plant oils. And since it cuts out most processed foods available on the market it might help you in other ways.

You can still eat plant oils with the whole plants they come from becuse you won't be able to eat even remotely close quantities of them this way.

Plant oils are not inherently safe. Canola oil for example is just rapeseed oil extracted out of plant variety that contain as little as possible of the poison that makes rapeseed oil not safe for human consumption.

The fact that we were able to breed the plant that doesn't immediatelly kill us doesn't mean it's fully safe to eat.