[zamadatix]

Google Maps automatically caches areas around your common saved locations (e.g. Home and Work). Outside that, what's the value? It's a bit niche to open your map for a cached rough outline of the planet.

I do wish the apps were a bit less stingy about letting you choose to fully offline large areas more easily though. The detailed road information is helpful when you don't have signal and if you travel for work it's often outside what a single box will capture. E.g. Google Maps lets you offline as much as you want (as far as I can practically tell) but you have to do it in many about-indiana-sized-rectangles instead of just saying "save these states" or being able to zoom out farther to a region directly.