Such tagging has zero benefit. It's only making things more complicated and confusing to others. Following your logic, everything would be mapped as highway=some_generic_path and had all access specified. highway=footway already specifies the right access and no proper routing engine will navigate cyclists/cars/horses through it. If a way is intended for cyclists and peds, use highway=path. If a way is intended for cyclists, use highway=cycleway. If a way is intended for peds, use highway=footway.