The NCDC units were crap anyway, in my view.
You're entitled to that view. However wrong it is.
CD would constantly be spat out in morning, due to condensation the the disc. The maps were very old, to the verge of being pointless. They don’t take full postcode, often struggled with industrial estates or where no traditional road/number.
So the system you have done *nothing* to for 17yrs occasionally spits a disk out? I'd wager you'd had at least 10 phones in that time. So I know which is the most trouble free
Numbers and Roads are down to the making provider, of which all satnav manufacturers use 2 in the UK, TomTom/Teleatlas and Here/Navteq. Its these companies that provide the road names and numbers. They also provide the postcodes, with varying levels of accuracy. Personally, I never use the postcodes, as its a great way to get to the wrong town.
Waze on the other hand, start app, says are you going home? Tap go and boom, multiple options based on live traffic data and dynamic routing updating as you go, based on traffic. Not once has it given me issues in position/routing.
I've used Waze, Goople Maps, and most other online services, and TomTom (both phones and standalone), Garmin, and all that tosh. They are universally useless. Even on an iPhone X and a Galaxy S8 in small American towns (far more open than UK towns). I can easily see why people drive the wrong way up motorways with these stupid devices, that should be banned IMHO.
Add in heat reflective screens, and they are truly lethal (in the hands of millennials and others born after common sense died).