That ton of layers is correct - each layer is the mask for.. well whatever you selected in cryptomatte, let's say Name as a default, which would mean you get one mask for every object, letting you isolate it with correct motion blur and depth of field.
This is easier in something that is not Photoshop, e.g. Nuke, where you should have nice nodes with a dropdown list so you can choose the object in question that way, but in terms of something like Photoshop this is what is to be expected from Cryptomatte. You can then use those masks as needed, e.g. copy them into the Mask of an Adjustment Layer to apply an adjustment only to that object, or use them as masks when blending Render Elements like Reflectance etc. Sadly Photoshop is just not very elegant this, though!