Offline maps. Browsers tend to delete PWA data without asking the user first, which can be as threat to life and limb in this case.

You can save files and load them from disk. You'll just have to have the user pick the file.

Yeah, but if the phone/browser decides to delete some of the PWA's code to save space, you won't be able to use any maps at all until you connect back to the internet.

Before you say "just download the code to your phone as a file", I'm going to assert that's exactly what an app is ;)

That would be worse than an app.