As far as I can see the lobe looks fine. Cam lobes have a thin hardened outer layer, once this wears trough it will wear very fast. If you run your finger over the lobe it should feel smooth, without dents or sharp edges. If it is really worn the valves get noisy. The scratches may have some effect on wear if they are big enough to break the oil film on the lobe. For the moment I would not do anything about it, since replacing the cam makes no sense if it not to badly worn.