This is actually outdated information. The inflection has already happened and the split is 40% Asia and 40% North America with NA losing ground over the last years and Asia gaining that ground.
Combine with that other markets also getting bigger like South America.
The reality is that NA had their smartphone / mobile boom already and the rest of the world is still catching up. There are more smartphones, apps, features, services, etc. to be gained by selling to the massive influx of new customers versus trying to cater to the old audience of North America.
My experience is that while other regions have a lot of users, my revenue is still 90% from the US for a location-agnostic product.
In the vast majority of cases, Asia and SA won't touch your product if you don't have deep familiarity with their markets, their idiosyncrasies and have a competitive business model there. Getting folks in these markets to pay isn't easy, friend.
And that's why we keep having these conversations in English on a US site about products made by US companies.