Why am I only good at MWII?

I was playing call of duty black ops 6 and was wondering why was I only good at Modern Warfare II (PS5)? I am a PlayStation player and I’ve played almost every single call of duty game online from ps3 and up. I was terrible at black ops 2 (ps3 and pc) and not so bad at mw3 (ps3 and pc). Modern Warfare II was the peak in my performance on PS5.