Don't think anyone other than Strava and Komoot have sufficient user-generated trail database to be useful for your use-case.

OSM has a heatmap feature. Users can contribute tracks and feed into it:

https://wiki.openstreetmap.org/wiki/Heat_maps

That's possible. I use RideWithGPS, maybe a lot of people use it around here. Or maybe only two other people have ridden the route, it doesn't say, but it's still super useful for finding routes.