I said Lingua Franca specifically to draw attention to the fact that no language stays in the position forever. Times change, and languages come and go. Latin came, and went, French came, and went, and English came, and will go, too. Many more languages have had their time in the spotlight, too.
As to the analytic/synthetic, English itself is mostly analytic by now; there's some more European languages that are fully analytic, and some that are somewhat analytic.
But more importantly, no characteristics of a language have anything to do with it becoming dominant. Nor does yours or mine hatred towards one or the other matter one bit. Language spreads not on it's own merit, but on top of other things. Demographics, culture, technology, trade, power... People who have business to do in China are already learning the language. It's a career accelerating move for the individual, and profit accelerating for the company. Since most of the business to do in the world is now in China, at one point the network effect will kick in, and the rest will be easy pickings.
And no, Cantonese is in no way in a bad position in this. It is the dominant language in the Pearl River Delta, which has good dibs on being the most important manufacturing cluster in the world.