Hi....  Consider your tagging of sidewalks.
Usually  we tag the sidewalk in the tagging of the mainstreet with sidewalk=left, right of both.
https://wiki.openstreetmap.org/wiki/Key:sidewalk

Otherwise you are a prisonar on your sidewalk. I would'nt route properly.
There is no consensus creating separate sidewalks.
In case there is a greenarea, parkinglots   between highway and footway we will create separate sidewalks.


Greetz,
eggie