“You need to look up Oneplus to see how many people were using their devices till they announced exit from Western markets.”

The final part of this sentence shows why there is absolutely no need to look up Oneplus.

Oneplus is owned/backed by Oppo. Their other phone brands like Oppo, Realme, etc. are really popular worldwide. They removed Oneplus from some regions (e.g. EU) where some of their other brands are more popular.

I'm not sure if you are from the US, but if you are, it really gives you a distorted image of what the worldwide smarphone market is like.

E.g. in many European countries, it is 1/3 iPhone, 1/3 Samsung, 1/3 others (which are mostly Chinese brands).