I won’t opine on what I think is going on here but… something ain’t right.
Maybe we can help by providing guidance to cater to us better.
I'll take a stab.
Cultures is a weird word. I'd use the singular.
The landing page is rather short.
There is a gallery but it doesn't slide.
The play store description also has some grammatical differences but maybe that's helping you rank, who knows.
OP, look into Chatgpt3 you can paste your literature to it and it can make it grammaticaly correct.
From within the app, looks like most users are South American. Large population, and there's a shortage of apps targeting the region.
This is just my perception, being someone builds for the Indonesian market, and having an app that hit similar numbers without any marketing effort.