That's interesting. OP might actually have the best answer lol.
Osmand, Organic Maps, Magic Earth are all clients that use Openstreetmap.org data. That's illusion of choice.
OSM might greatly benefit from being adopted by Big Tech as a way to oppose Big Tech (research Overture Maps), but as of now OSM absolutely sucks and is firmly determined to stay that way (just read the discussion on OSM forum about Overture Maps and you'll want to cry).
On, the other hand, Sygic is closed source but works offline and based on TomTom maps, which should be closer to Google Maps quality than to OSM lack of quality.
So you can download Sygic, (sign in with some temp email if you must,) download the offline maps, remove network permission and voila. Good quality offline maps!
In a year you clear the app's cache and storage, give network permission, update the maps, revoke network permission and voila. Updated maps without forking out your data!