As a reader, I was annoyed that there still doesn't seem to be an app, so I made a basic reader app myself:
Works completely offline, Windows, Android, Linux, library sharable between devices in the network, basic search for stories.
I want to add custom color theme support and table support in chapters, and it's good to go. Next would be an advanced search like the series finder, and support for more websites.
The app is an open-source Flutter app under the MPL2.0 license, though I haven't uploaded the code yet.
If someone wants to try it (maybe in a VM, because who trusts random strangers on the internet?) I can upload a build.