Frame drops while playing Pubg mobile

I am playing pubg mobile on my iPhone 12 but what I have noticed while playing was that FPS remains constant between 30-40 FPS .It rarely touches 60 FPS.

Lol I got better gaming performance on my older Oneplus 5 which gave me constant 55-60 FPS.But on this iPhone 12 the game remains very choppy.

While releasing the phone apple authorities declared the phone to be the most powerful phone but basically it’s unable to handle games and give out its peak performance.

Any solutions?