Having prepared this reply I now see your later edit! … There are reports that users can sometimes switch from a LineageOS build of the same Android version but …
If you simply mean as in your first post
No system choice in bootloader.
Maybe just, "there is no bootable image on /system ".
Edit in a quick search I cannot verify your system partition information, but are you reassured that /system exists, but is corrupted in some way?
/e/ install pages used to include a prerequisite section in red which read
Caution: Do not install /e/OS on top of a higher version of stock OS.
Before installing /e/OS ensure your device has the latest stock OS of the same version as /e/OS.
If only lower versions of the stock are available then install the last available lower version before installing /e/OS.
Maybe it was thought that this paragraph is a bit clumsy and not device specific, but please bear it in mind if you follow this suggestion.
I think the best thing to do right now is to search how to get the latest Asus ROM for the device; you might try
As you have working Fastboot mode there should be no problem flashing the device with a Factory ROM.
There is another thing to be aware of. Quoting from this week’s Week 44, 2022 : Development and Testing Updates
End of official support for Nougat, Oreo and Pie
For Pie, Oreo and Nougat the official /e/OS support draws to a close.
Reasons for dropping official support are:
- newly released applications like App Lounge, Advanced privacy code has not been customized for these OS versions.
- lack of dedicated ROM Maintainers
- no support upstream (Lineage dropped support for Pie sometime back)
- device trees will continue to exist in the Gitlab and users with build skills can create custom ROMs on these builds
- Security patches and vendor patches for the Pie, Oreo and Nougat code will be updated based on availability.
Google stops security patches for OS after some time. Similarly, Vendors drop support for older models when they release newer models in the market. Then it depends on developers from various communities to backport the patch
We probably did not have reports that the last /e/ ROMs from April 2022 were faulty or they would have been withdrawn … but the label “Beta” is a clue that this is going to be a bit experimental, I think.