It's wild that they needed this even explained to them, but I figured as much given how terrible Maps and some other Google products are at working in offline mode. One of the most basic features in Maps, simply adding a pin to the map, has been broken for many years if you don't have an active internet connection. There's absolutely no reason you need internet to save a pin locally and it originally worked fine, but they clearly can't be bothered to fix simple glaring issues like that now.

I can recommend Mapy. You can download maps per country, state and even region, so not overly much storage space used. Route planning and navigating offline - it even let's you plan tours based on kilometers and/or time (this is particularly nice when hiking in an unfamiliar region). Modes are: car, bike, mountain bike and foot. I've been using it for years now and like it a lot. It's free with some premium options, I believe. https://mapy.com/en/

Thank you for your service. I spent a few years traveling all around North America and I can assure you that offline mode is very necessary for Maps. These Bay Area engineers need to go to the Rocky Mountains sometime and see how their phones act there when they have zero connectivity.