Breaking the physical separation rule for some road markings

[jidanni (Dan Jacobson)]

I was just reading

No, the all the lanes don't intersect in a single point, except in ant farms

The guideline is that highways should be mapped separately if there is physical separation, but it doesn’t strictly imply the reverse. See e.g. recent thread Breaking the physical separation rule for some road markings

and wondered, was there some motivation in the early days of OSM to save on vectors. Like each additional meter of vector was costing big money or something?