Are they stupid

Human nature.

These countries have somewhat united through consumer goods, and the consumption of resources, but unlike a free country they don't all share the same values, morals and beliefs. That is why America seems appealing to those living in strife. Unfortunately any country can change their operations, and be overruled with corruption. This is the reason why the world will always need borders and order to keep the peace. But today corruption has made it impossible for the average person to obtain justice, and today corporations have more freedom, protection, and rights than its own citizens.

It would be an incredibly unstable union due to cultural, religious and ideological differences.

The reason we can't unite is simple. Cultural differences. People everywhere have different values, customs and traditions and there are inevitably going to be other cultures that disagree with specific ideas and values. While world peace is a great goal for the future, global unification wouldn't work. What we should strive to do is preserve each country's individuality while working towards world peace. Different cultures not mixing is just human nature. Nothing more and nothing less.

I'm very good at convincing people to unite. My charisma is high and I talk in a very convincing way.

When dealing with terrorist groups like the Taliban, Al Qaeda or the Houthis, that wouldn't get you very far. We need peace through strength.

You're right though

Someone like Kim Jong Un or the Hamas leader would simply shoot you dead. Most people are stubborn with their beliefs, and will not change their mind based on some random communist kid

As someone whose played MANY competitive game and moba with bad matchmaking…

Yes a group humans are beyond brain dead.
Watched a shinbi and drongo type college thesis’ at each other only to agree to attack a jungle boss…

While the crunch took our last tower and solid our core…DONT WORRY THOUGH THEY GOT THE JUNGLE BOSS.

yes, we are stupid