Please do help me

Hello everyone, First of all thankyou for spending your valuable time reading this. I have had a smartphone which decent when it comes to gaming and even tho I usually set my graphics to it's lowest in games such as Genshin, It still lags while in reality it shouldn't, I don't really know what's really causing this as the specs of my android isn't even that bad if there's anything that you can tell me what's causing this I would really appreciate it.