Why is A70S and higher series getting late updates where as M31 A51 which are inferior to our devices getting early updates than our devices. Its just my question

After the 1st august update in my A70s battery is draining a lot even wen its ideal and before I was playing call of duty mobile a lot and there were no heating even after 3hrs of continuous play now withing 20 mins its heating a lot

Received android 10 update on a70s and Feb security patch

From past 2 days I'm facing battery drain on a70s before a single charge would give like 1 day backup according to my usage now it's only like 12-13 hrs