If you see streak marks on your windscreen it probably means the rubber has worn. This would cause cracking or splitting on the wipers, or it could be from debris, from grit or dirt.
Skipping happens when wipers aren’t used very often. The rubber may be out of shape from heating and cooling. But if this happens when it’s raining then you will need to get them changed,
Squeaking can normally be resolved from tightening or loosening the wiper arms. However, if this issue isn’t resolved after a few little changes then it’s time for a new set.
Smearing is caused by worn blades typically. But can also be from a dirty windscreen or poor quality washer fluid. If you have cleaned your car and changed windscreen wash then it’s a good idea to get them changed!