Last time I tried with Google I could only download a relatively small area, and it would only be available temporarily.
With CoMaps, I can download entire countries and keep them forever. That's pretty different.
Maps.me used to be an open source project, when they took it closed source and tried to commercialize it, the last open source version was forked and is now known as Organic Maps.
Then the Organic Maps maintainer started acting sketchy, introduced a paid partnership with Kayak and generally not behaving in a very community minded way. Organic Maps was forked and the new version is now known as CoMaps.
We'll see how long this one lasts.
I'd see if an LLM can help you get the data, build you a migration tool, and help you migrate it.
The area you can download is still pretty large - whole cities, big chunks of countryside. I'd put money on the fact its good enough for most people's uses.
I don't know anyone (and I mean exactly zero) who ever used the offline feature of Google Maps. Online is good enough for people who almost always have an Internet connection. What happens when they don't is that they don't have access to the map.
People who care about having offline access (because they live in a place where they don't always have Internet or just because they care) don't bother using the Google offline feature. They use proper offline maps instead. Maybe in parallel to Google Maps: it's possible to have Google Maps and CoMaps.
Have lived in Alaska. Used offline Google maps. Worked perfectly for years and years.
I've used it plenty for things like driving trip to remote places with poor signal (e.g. where you'll want to be able to get directions back to civilisation) and foreign cities (when you're on a phone contract with bad overseas data prices).
Worse, without a net connection you can’t even get the phone to start a route.