You have succinctly described why we hate these OEM headlights (i.e., the plastic lens headlights on '85-93 cars). There is no discernible center of the low-beam because the headlights disperse the light uselessly, and any higher than background illumination is concentrated on the pavement (uselessly) a mere 20 feet in front of the car's bumper. If you are foolish enough to try to aim the low-beam higher, then your high-beams do little more than illuminate treetops or 3rd story apartment windows.

It's all the fault of the USA's DOT, which mandated these awful headlight requirements. And you can see why so many of us have switched to euroheadlights, which have useful, well-focused beam patters with sharp low-beam cutoffs.