Anbox being slow is not a big surprise though: it literally runs a complete Android system on top of your OS.
We need native, lightweight apps for the phone and that requires a big amount of work for sure.
There's an Android port for the PinePhone that I want to try one of these days. Back to an OS whose roadmap depends on Google, but at least without the proprietary blobs. But I don't plan to settle on it. As someone said elsewhere in this thread, it's less and less hackable, and I hope that GNU/Linux-based OSes work out.
Either you haven't heard of or used Gnome Maps (which is wonderful, highly recommend), or it doesn't fit your criteria. Assuming the latter, what do you consider missing?
OSMAnd is able to show all kinds of details about roads (such as the road surface – important for cyclists interested in asphalt/unpaved riding).
Gnome Maps also uses GraphHopper for routing. OSMAnd, on the other hand, allows you to extend its routing with plugins, so long-distance cyclists can install the Brouter routing engine that is superior for this kind of travel.
The same is also true of map apps. There just isn't enough developer manpower to make vanilla-Linux mapping apps as featureful as OSMAnd or Maps.me's open-source fork, and therefore the best thing to do would be to emulate them using Anbox, but the Pinephone's hardware is just too underpowered to comfortably do this.