Why is my iPhone 11Pro Max slow

I have noticed that my iPhone 11Pro Max is slow and and glitches in some apps it never really loads the information or it simply doesn’t load at all. I have noticed it even more in CallOfDuty Mobile when my son’s iPhone 11 loads that game faster than my 11Pro Max.

to unlock my phone is also a waiting game because sometimes while trying to unlock my phone with faceID it takes way longer that usual. What’s happening??