Something has changed regarding minimum requirements?

ive stopped playing shortly after argent tournament, came back here and there for few arena games etc, but didnt last very long, anyway, now that ive come back ive noticed huge performance issues on my Ipad air, the game basically becomes unplayable after certain point when i have literally around 2 fps, overall the performance changed drastically and battlegrounds are literally unplayable for me, ive barely had any problems few years back playing on my device, game lags in collection and the animations are killing my ipad, how can i lower the performance?