When bushwalking there are two sorts of routes - on and off track. Graphhopper is very useful for tracks, but not for off track journeys. It would be nice if a user could put waypoints on a map and Graphhopper joins them. Also, the times are optimistic.
Finally, sometimes there’s a gate, often at a car park, with provision for walkers to get past the gate. This may be a stile, a narrow opening or something else. Graphhopper sees the gate as an obstacle and will not let the route go through the gate. For bushwalkers, gates on Graphhopper should not be an obstacle.