How could his 3 year old iPhone be sluggish as shit? Mine is 3 years old and still feels as snappy as when I purchased it, usually they get sluggish around the

How could his 3 year old iPhone be sluggish as shit? Mine is 3 years old and still feels as snappy as when I purchased it, usually they get sluggish around the 6-7 year mark, in my experience.