These cars are already 3 years old when imported. Then either stay at a dealer for 6 months-1 year or spend a lot of time in shipping and clearance and stuff.
Usually they last 5 years out of which 3 have already passed. 5 years is a lot for a battery but since we dont get the total 5 years so we feel like gaari achi nai and jahil people start blaming the car.
Then comes the replacement part, You cant find new batteries, only kabli are available which are already used a lot and years old so they aernt going to last longer either.
The best you can do to prolong your batteries life is to keep the hybrid fan clean. Change the heat sensor position closer to the center of the battery so that it turns on earlier since center of the batteries starts getting hotter quicker, the cooler than batteries remain the more efficiency they give.
Lastly models after 2015 had improvements and last longer but for before 2015 you cant do much