Fully agreed - the amount of data openly available is astounding. I think many people would be surprised at the richness of the tagging information within OpenStreetMap. Without OpenStreetMap, this project and countless others would not be possible.
Mapping costs would be by far the biggest one. However, I'm very lucky that after the last big spike in traffic, Mapbox very generously admitted me to their community programme. You can read more about that here: https://trailrouter.com/blog/mapbox-community-programme/
The server costs are quite modest at the moment (under $200/mo), which I'm lucky enough to be able to self-fund through my other work. If usage were to massively increase then maybe I'd need to find a way recoup costs. But even all of the hits from HN have barely put a dent in the server utilisation, so there's plenty of headroom for the foreseeable future.
Mapping costs would be by far the biggest one. However, I'm very lucky that after the last big spike in traffic, Mapbox very generously admitted me to their community programme. You can read more about that here: https://trailrouter.com/blog/mapbox-community-programme/
The server costs are quite modest at the moment (under $200/mo), which I'm lucky enough to be able to self-fund through my other work. If usage were to massively increase then maybe I'd need to find a way recoup costs. But even all of the hits from HN have barely put a dent in the server utilisation, so there's plenty of headroom for the foreseeable future.