"a more integrated global political and economic structure" and a "better world" are independent goals. Billionaires and owners of huge corporations have always preached for weaker borders not in the sense of John Lennon's Imagine, but in the sense of free-trade agreements that allows them to expand their market at the expense of local economies.

Take China. China is incredibly protectionist but it has one of the world's biggest markets; its population is huge and lately their purchasing power has been steadily increasing (aka. more disposable income to buy stuff). It's no wonder Apple, for example, has made so many strides to hit the Chinese market, but it has had to go through hoops and I bet unbelievable amounts of red tape. "a more integrated global political and economic structure" would mean less protectionist policy and less friction for overseas expansion.

I don't think anyone disagrees with the idealized notion of making the world better. But there's tons of room for disagreement in how to do so.

I've even heard some argue that prosperity is a limited resource, and that "globalists" naively believe there's enough of it to spread around the entire planet. Obviously if you're already well off (U.S.) then there's only one direction for you to go when the spreading happens: down.

FWIW, I don't believe in this line of thinking. But, I think there are some interesting theoretical considerations that I don't fully understand. The idea of prosperity being a limited resource is, at least, interesting to think about.