What do you mean so few? Why would it have to be few?
Well what's your thinking? Have a large number of people in control? Perhaps have these people control certain territories? These territories could easily manage democracy if they're small enough. I've got an idea... let's call them nation states.

Depends how it's implemented. What problems would those be that we don't have already?
Nationalism in nations that don't currently have problems with nationalism.

Unlike now huh.
On a much larger scale.

How does a global government keep control? There is only one sensible answer to that... by force. You're talking pure tyranny.

That article you post only serves to fuel conspiracy theories about how covid has been manufactured for the purpose of advancing a world government agenda.

How does a world government reduce inequality?

Quotes from article...

If a federal world government were elected democratically...
How do you propose this happens? Do you think there is a global appetite for it? How do you enforce an election on a nation that already has a democratically elected government? Overthrow them? How is that democratic?

A fourth problem is that those with economic power can avoid taxation.
How does this not apply to the global government? Do you think they will happily pay tax? What makes you think a global government wouldn't itself be corrupt?

Curbing the power of multinationals
This seems incredibly naive, I would expect the exact opposite to happen... multinationals would become even more powerful and corrupt.

I don't think you realise quite what you're in support of here. Totalitarianism, that's what. You're removing the right of self determination for literally everyone on the planet, and you can only do that by force. Even if somehow we democratically voted for it, can we democratically change our mind if it's not working out? We can see how difficult and problematic that is when we talk about a much smaller and much less powerful continental government.

I'm in no doubt that a world government can solve some of the world's problems, But it will crate many more. It can only work by force. I don't see why you would have any reason to trust the world government more or even equally as much as national governments.