I've heard similar pitfalls about Kindle Scribe, the write-able Kindle.
When I am trying to focus on reading a book, I appreciate that the Kindle doesn't have too many bells and whistles. I don't want notifications popping off and the distraction of fast Internet access.
Not saying you're wrong, just that your anecdote doesn't mean much about $100/$50 Kindles.
I'm talking about aesthetics. In this case, elegance, utility, responsiveness, durability, efficiency .
Unless of course you read books that have graphics or come in pdf form.
I consider myself a heavy user of ereaders, probably averaging over an hour a day, and have had a few in my time (Kindle paperwhite, Kindle Voyage, Kobo Aura H2O, latest the Kindle Oasis - which I got in Jan 2019). The only real time I felt like I got an "upgrade" was the slightly denser screen on the voyage, then the slightly larger screen on the Aura. The Oasis feels functionally the same for my use case (again, 99.9% text, no images or diagrams or animations, so can't compare them). But really the only reason I "upgraded" after the voyage is leaving it on a train or got damaged in my luggage one time.
And what can they really improve on it? There are denser screens - but they don't make the font size I use actually look any better. There are larger screens, but it's already about the limit of what I want for portability, and much larger would be harder to read not easier. There are faster refreshing screens, but I've never even noticed the page refresh speed, as it's lost in the time it takes to realign my eyes to the top of the page anyway.
So what's left? Looks? "Premium" materials? Thinness? The oasis is already at the point where any thinner or bezels any smaller and you couldn't hold it. I don't read comics on it, so don't really need a higher resolution, or colour panel (though can see the advantage if you did). Same with flash size - every book I've ever read on it (nearly 3000) is still on my 8gb model, and it's not even at 50% capacity.
And now my Oasis battery is starting to fade - it doesn't more than a few days anymore - and somehow it feels weird considering buying the same thing again - or pry open the back off and try to replace it - though who knows what that would do to it's water resistance. I guess the newer models have an amber backlight option, which would be nice, but still doesn't feel like an upgrade to something I purchased over 5 years ago now? Or even more as I only got that because the (functionally equivalent) predecessor got crushed on a plane.
So I think my point is that for the "Reading Books" use case, a kindle has already reached the maxima. Any "improvement" would almost be a waste - why improve refresh times when it won't actually affect the user experience one bit?
Is there something I'm missing? Is this just a local maxima where you'd look back on and feel stupid for not seeing the "obvious" improvement path? Or is ereader "development" just a waste now as it's now just a commodity?
A handle. My hand is not L-shaped. Make it hand-mirror shaped and shift as much weight as possible into the handle. Preferably a fold-down handle.
A folding screen. Or rather, two screens with a hinge, no need for fancy flexible screen tech. It doesn't matter if there's a visible bezel between the screens, you're only displaying text. Ideally, you'd cram it just small enough that it can fit in your pocket when folded.
Also, once you have a handle you don't need bezels.
I can't imagine holding a hand mirror for any length of time comfortably - especially if there's only a single orientation you can grip it with the screen upright - but that may be the weight distribution as you mentioned.
Folding would be useful for putting it in a bag or fitting it somewhere, which hasn't really been a big issue for me. A flat profile is already fine when putting it in a laptop bag - it's thin enough it just slides down the side of the pocket. I wouldn't be surprised if decreasing the total volume is pretty much at it's limit already with being able to be held - but maybe putting that is a more square package when stored would be easier in some cases?
So maybe zines and comics is where ebook readers are heading.