It's not fair to compare web browser downloads to LalaWorld app..
Everyone downloads new web browsers to test them out, just a browser with built in ad blocker, that's attractive to test it.
Have you heard of cm browser? Also has ad blocker, 50 million downloads, and plenty web browsers have 10 million downloads or more.
I mean, I just don't see the connection you're making, what similar channels can we learn from?