This post is about an offline maps app which is maintained by volunteers, so it can't be that hard for the likes of Google.
I’m actually not even sure what the complaint is actually about since I don’t use offline myself, but I know that Google Maps is a massive app with tons of teams all working on a myriad of features in parallel and a huge dependency tree. So I’m not surprised at all if there are a bunch of features with online assumptions baked in.
1. Offline maps don't actually download all the destinations in the mapped area
2. Google maps is bad at displaying densely packed businesses - this is an issue online as well
3. No offline bike or transit directions
These are the 3 I checked immediately in organic maps, and all work significantly better there.
I think your point is reasonable, but I'm also a very high income person who thinks nothing of buying data plans when traveling internationally and has an unlimited plan in the US. I routinely meet people while traveling who have the opposite set of financial priorities, organic maps is probably a great choice for them.
Anything can be done. But you can't do everything.