You have to count the street lights to find the right one, and the McDonalds is probably easier to spot than any street sign . . . (what you probably prefer is that counting street lights gives some sense of distance (in an urban setting, at least . . . I've had that "third light" instruction when it was, literally, miles).

but the street light is still a landmark, not a distance or direction . . .

All "directions" begin with a landmark (point of reference), even if it's just "where you are".  The difference is whether your destination is "South 3.2 miles from the intersection" or "turn right at the intersection, it's across from the CostCo".