That can't possibly be right...
The world population is 7.8 B. The population of India, where the app is banned, is 1.4 B.
That'd mean that if everybody besides people in India downloaded this app, it'd be 6.4 B downloads.
But not everybody outside of India can download the app. This would be a pretty generational thing - people aren't born with devices that can download apps, and older people generally don't download apps. There's 2 B people under the age of 15 worldwide, and 750M people over the age of 65 worldwide. 450M of those people are in India, so don't double count them, but this leaves us with only 4.1 B worldwide who could download this app (and I'm not factoring in all the people who are too poor to have a phone able to download and run the app).
All this to say... if there's really 3 B downloads of this app, that means nearly 75% of everyone who could download the app has downloaded the app. And there's no way that's right.
You may be correct.
But considering TikTok has 1.1 billion monthly active users... we know they have at least 1.1 billion downloads.
Maybe people downloaded it more than once?