Are the symptoms of cervical spondylosis bad?

Can be. Cervical spondylosis- arthritis of the neck usually manifests itself in neck pain and sometimes arthritis spurs which narrow the nerve exit hole(foramen) and the central spinal canal which can cause weakness and pain of an extremity as well as weakness of the arms and legs. It can also be mild. This is a significantly variable disease. See the neurosurgeon or orthospine surgeon.
Not necessarily as . The symptoms can range from nothing to varying degrees of pain with or without nerve symptoms & findings if nerve tissue compressed or irritated radiating into arms &/or legs including : pain, numbness , tingling (parathesias), & even weakness with or without pain radiating into extremities. Headaches can be caused as could gait/balance issues as well as poorer dexterity &handwriting.