Yes, there are many applications (mirror) consuming OSM data for assistive navigation. There are also applications using OSM data to power “headless” navigation in wearable devices. However, none have the brand recognition of Apple Maps and Google Maps, which people with disabilities have gone through great lengths to cope with, even though these applications aren’t optimized for their needs.
Well-designed assistive navigation applications are very different than mainstream navigation applications. For example, Nearby Explorer was an OSM-based navigation application (and POI editor) for visually impaired pedestrians that was developed by the American Printing House for the Blind (APH), a major nonprofit Braille publisher in the U.S. The UX was much more explicit about the user’s surroundings than in a conventional application. APH’s indoor mapping team demonstrated how to use the application at State of the Map U.S. 2019. As proof that people used it, you can read reviews of the application by and for blind people in AccessWorld and at AppleVis, an iOS blind user community. Last year, it was discontinued in favor of a commercial application that unfortunately doesn’t appear to use OSM.
Openrouteservice has a wheelchair routing profile with lots of fine-tuning options, but it’s somewhat obscure outside the OSM community. Wheelchair users especially rely on public transportation, so probably many are using popular transit planning applications like Citymapper, Moovit, and Transit. Public transportation agencies have deployed their own OpenTripPlanner instances in some metropolitan areas, most notably TriMet in Portland, Oregon. These multimodal routers use GTFS feeds for the bus and rail connections and OSM data for sidewalks and other wheelchair-accessible paths, ideally leading from the bus stop to the doorstep.
Apart from navigation and trip planning, transportation analysts and planners also use OSM data to plan improvements to a city’s pedestrian network. Pedestrian and cycling advocates similarly use OSM to propose safety improvements. Everything including roads, sidewalks, curbs, and POIs can be relevant to this kind of analysis. In my metropolitan area, the public transportation agency wanted to help us get sidewalks, bicycle lanes, and POIs into OSM so they could more easily evaluate options for bus routes and bus stop locations. Each city that the agency serves already had all this information, but it was siloed in many incompatible datasets, whereas OSM could federate these datasets together in a single database.
This is just scratching the surface, but hopefully it gives you an idea of the breadth of possibilities with accessibility-focused data in OSM.