But for encounters it'd be nothing interesting. So what if the molerats were a bit meaner, everyone would just run away like always. Encounters are good as nothing if the encounterer doesn't care. Even worse would be if the encounters became so dangerous that they couldn't be avoided. Players might just go like "Night time? Time to go afk or do something else outgame"
Having a "worldmapless" travelling requires a fuckload of mapping, looks shitty as the map looks too flat and takes a mass of computer ressources. I see not a single reason why this should be implemented, and will most likely never happen on 2238.
I don't think such thing will ever happen. It would require a lot new graphics for mountains and hills and whatnot, so that the maps don't look extremely flat.