Release the cam followers, and pull the camshaft out of the head. Then you can see the cam bearing surface, the cam itself to know the actual condition. If the bearing inserts are scored and damaged, you can leak a lot of oil through the created excessive clearance, reducing pressure within the whole system. A lot of the oil will flow through the easiest exit, and the other bits get less than normal.
What your pictures is possible cam bearing damage. Cannot tell w/o removing the cam.
Lack of lubricant in the pan decreases pump output, and the passage to the cam bearings is sort of roundabout. The oil flows up from the block, across a narrow passage on the bottom of the cylinder head, around a head bolt(peripheral flow) into a passage in the head that leads to a gallery that feeds the cam bearings and the lifter supports.
If you look at the bottom of the head, near the edge, drivers side rearward area you'll see the small volume that connects to a cylinder head bolt hole. That's how oil gets to the cam bearings & lifters.
tom