Do u live in some place less humans live? Like a village or something? OSM is mapped by volunteers, which means that less OSM enthusiasts around you = worse mapping. Perhaps you could start a little bit of mapping?
As for the voice navigation, well Organic doesn't have its own voice. It uses ur phone's native text to speech engine. If u have completely degoogled ur phone, then u probably would be using some other tts engine (which most probably sucks ass).
As for the searches, yeah, they need a better local search engine.