@DazeEnd I find OsmAnd works very well. It'll depend on the data around where you are, of course, in my experience it's very good. (I use it on Android but the data and navigation are the same, and I think the interface is basically identical.)

https://osmand.net/

@DazeEnd virtually all OSM based ones don't do live traffic, so if that's a must you'll be disappointed unfortunately.

I'm contributing to @CoMaps which is based on OSM data and works offline once you download your local maps and use it as my main driving direction solution (it also works with CarPlay). How well it works for you depends on your local OSM data quality. As it's free and open source you can try it out and see how it goes 😊