OsmAnd routing works OK for biking, but I specifically meant BRouter.

The first thing I noticed was that it's a lot faster - I get the routing results almost immediately, even on a low spec phone (with the drawback that you need additional space for the routing segments).

The generated routes are a lot better, too. They make more "sense" from a bikers perspective, because BRouter is elevation-aware. It also gives tracks that are on official cycle routes a higher priority (can be disabled). I tested it with trips I usually cycle and it calculated routes that were very similar if not identical to the ones I chose myself. That's what I expect from a good routing algorithm.

Test it yourself: https://brouter.de/brouter-web/