What does “waymarked routes” mean, exactly? And same question for the OP.

Doing OSM editing from Mapillary imagery in various US states, I find that the roads that have roadside signage as “official bike routes”, predate modern safe(r) bike infrastructure. These are often highways that frankly look like death traps: no shoulder, high speed limits. Especially when so many North American long-haul cyclists now are riding “bikepacking” setups, it may be preferable for a router to prioritize quiet agricultural tracks and other unpaved terrain over the supposedly official bike route.