Iphone Going down slower when i update

My iphone 13 has completed 1 yr and 2 month old n feel too slower then my sis iphone13

real thing is that i run the bench mark on my iphone n my sis iphone i have seen a very big difference between them i got 971 of the score on bench mark or my sis iphone hv 2217 what a big difference on it , i cant play games coz its very slower by day to day n when I updated my phone i cant play games like last i play when its new or it’s getting down n down slower or its going thru 2 years old my iphone 13 be like not more useable n totally lost of bunch of money or after 3 yr its die when i buy my brand new iphone i hv lot of best thinking that i use it for long time without any issue but ill worng its getting lots of bugs n probluems i want my money back thats it i want my best android back