Appealing isn’t the goal. Catching someone’s attention is the goal. (Nobody thinks the balloons on the cars at the car dealership look good but statistics prove that balloons sell cars.) Then, triggering someone’s curiosity, which is more where the copy comes in. (You can increase your click count with this one weird trick!)

You’re subject to it every bit as much as me or anybody else, but for whatever reason, we have different triggers than the Mr. Beast crowd. People that think they’re immune to it after having it pointed out to them are likely just less aware than most how their emotions are being manipulated by things they don’t even consciously perceive. Sales guys love people like that.

It doesn't have to be appealing, it has to make you click.

Car crashes are not appealing, and yet it is something most people are tempted to look at. Many people think of dopamine as the pleasure hormone, not really, it is the motivation hormone, pleasure is one way to achieve that, but so is horror.

It makes evolutionary sense, if something horrible happens, you better pay attention, to get prepared so that it doesn't happen to you.

I don't know the details of the psychological response to Mr Beast thumbnails, and I think neither does My Beast himself, the analytics say it works and that the only thing that matters to him.

Novelty goes a long way, old enough YouTube video are optimized for their time period and end up looking stylized in their own ways.

Fashion swaps styles fast enough most people can’t afford full wardrobes before it changes, which by default keeps each style looking fresh.

Maybe not appealing but interesting. Distinct enough from the rest of the thumbnails on the page to trigger an impulsive tap or click.