I'm sceptical Chinese will ever replace English as the most important language in the world.
Here are my main reasons:
- The population of China will turn around and start going back down before it can happen.
- China won't colonise the world and force their language on people at gunpoint like Europeans did.
- Learning Chinese takes people ~2-4x as much time and effort, depending on their original language.
So, unless Chinese is 2-4x as useful, people will usually opt to study English instead. And the more that do this, the stronger the positive feedback loop inducing others to do the same.
Will Chinese be 2-4x as useful as English for a lot of the world's population soon? I don't think so.
(Keep in mind they have the same number of L2 speakers, and English speakers are generally richer, more international, etc. The total income of those speakers is probably 2-7x as much today, though I'm guessing there.)
So we could plausibly be stuck with English as the dominant language of international communication for the next 200 years.
The ability to change the world's lingua franca may have mostly expired, being enabled by an era when violent invasions followed by displacement of existing residents and massive population growth among the colonising population was considered acceptable.
Did we force the Indians to learn English at gunpoint?
Took over the government by force and ran it in large part in a foreign language forcing people to learn to coordinate with their 'leaders'. In broad strokes I'd say that's forcing (some) people to learn at gunpoint.
Certainly indigenous Australians were forced violently to stop speaking their language and learn English when e.g. their children were stolen from their parents.
Figures on approximate language difficulty : https://www.clozemaster.com/blog/how-long-does-it-take-to-learn-a-language