That was to save "battery life" for old weared out batteries according to Apple. 
Xiaomi can mess up with updates too.
The last one for Redmi Note 5 11.0.2.0 has horrible lag issues. Confirmed by pretty much everyone, my friend even switched phones.
While the Chinese variant got 11.0.3.0 whose changelog said: "Fixed lags" which the Indian one never got. And I've tried both, the Chinese one is significantly smoother with almost 0 lags.
Since then I've unlocked, flashed an older MIUI 10 and relocked. We use our phones through apps anyway and those work fine. Camera sucks tho, but meh.

Xiaomi can mess up with updates too.
The last one for Redmi Note 5 11.0.2.0 has horrible lag issues. Confirmed by pretty much everyone, my friend even switched phones.
While the Chinese variant got 11.0.3.0 whose changelog said: "Fixed lags" which the Indian one never got. And I've tried both, the Chinese one is significantly smoother with almost 0 lags.
Since then I've unlocked, flashed an older MIUI 10 and relocked. We use our phones through apps anyway and those work fine. Camera sucks tho, but meh.