Is cervical spondylosis different from knee arthritis because of the shape of the joints involved? Neck seems to be more bothersome than other joints!

YES!!! Degenerative disease of the knee compared to the cervical spine is certainly different! the major difference is that nerves traverse the joints in the cervical spine, which can get "pinched" or irritated directly.
More nerves ; joints. Biologic process of arthritis is similar in neck and knee. But there are multiple joints involved in the neck with accompanying nerve root irritation and muscle fatigue that can cause harsher symptoms.