It happened mostly that available devices fails to target a reasonable usage and industry do not want it anyway.
The reasonable usage means A4/B4 size, to read most common pdfs, to be loaded locally via USB or LAN not by some third party proprietary service, driverlessly, no app needed. A FLOSS base to let's say synchronize with Zotero or some personal note tool, that part developed by a community thanks to the FLOSS base.
Another reasonable usage is 6-7" maximum for those who want paper like notes, again locally sync-able with a desktop/mobile not needing any third party or special software in the middle.
A third reasonable usage is as a desktop secondary monitor to be used to read without burning our eyes, or with raster graphic apps no special software needed as well, just a standard displayport/HDMI.
The reasonable usage means A4/B4 size, to read most common pdfs, to be loaded locally via USB or LAN not by some third party proprietary service, driverlessly, no app needed. A FLOSS base to let's say synchronize with Zotero or some personal note tool, that part developed by a community thanks to the FLOSS base.
Another reasonable usage is 6-7" maximum for those who want paper like notes, again locally sync-able with a desktop/mobile not needing any third party or special software in the middle.
A third reasonable usage is as a desktop secondary monitor to be used to read without burning our eyes, or with raster graphic apps no special software needed as well, just a standard displayport/HDMI.