adb remount does not work correctly on api 29 when running from the emulator. The command works fine on all other emulators that have been tried (18, 23, 25, 2
See @KiddTang answer which seems to be an actual solution
This issue is still occurring now even with API 30 (API R)! And even when starting emulator with writable-system option: (emulator -writable-system -avd NAME_OF_DEVICE)!
I found there is an existing issue for it in Google's issue tracker.
I tried following these instructions to disable-verity and reboot before remounting
However this solution caused my emulator to freeze/hang, and never booting.
Note: I am experiencing the current issue when using the emulator with the "AVD" provided "Android Sdk Images". Its possible however that this kind of images are limited somewhat. So it might not occur for other types of Android Images
Summary of Code from Link:
This code did not work for my situation, as it causes the emulator to freeze and wont start after rebooting, however, they may work others.
See the link for additional details and caveats.
Use the following sequence to perform the remount.