Why high price mobile phones not used 5000mh batteries?

1- It is possible some mobile phone manufacturers expect higher priced phone to be used for more things, this means they use more power, the lower mAh batteries may be able to supply more power when needed without over heating, the higher capaities tend to be lower power output batteries meaning they could be more prone the thermal degradation, this would mean a shorter service life overall.

It may be that a 4000mAh battery can supply 40w of power without excessive thermal degradation but a 5000mAh battery can only supply 25w of power, but the phone uses up to 40w of power when running several apps at the same time making the higher capacity battery useless or a risk of overheating and causing other damage

2- Because in premium prices smartphones have a good quality super Amoled display. amoled display consumes less amount of battery compare to LCD panel and it’s OS is very well Optimised or big battery makes your smartphone heavy but the premium phones are light weight.

Thanks for reading..