Checking in from Germany: By now I mostly use Naviki. It‘s based on open street maps as far as I know and it does a great job on road bike routes. You can preselect which bike you use, how fast you go, if you prefer direct or fastest route. The road bike option chooses smaller streets where you can ride undisturbed. Cannot recommend it enough!
As alternatives and to double check my routes I tend to use Strava, komoot and the Garmin heatmaps. All of them provide reasonable routing as well.
My routing experience is mostly based in Germany, Austria and Poland, but I‘d guess Switzerland and France will be of equal quality.
My secret tip is http://www.quaeldich.de/karte/ It‘s a map service from a Berlin travel agency and they have their qdtp database, which is a curated dataset of GPS tracks that make nice road bike tours. Every route was ridden by a trusted rider, so you can be sure if the track is in there it‘s of decent quality.