Too many limitations on this product.
Bottom line is that in its current state, this color ink technology is not mature enough and has a lot to improve before releasing some new products.
The Kaleido 3 screen that most of these color e-readers use was released in 2022. No new advancements since then in this space. Kinda sad but these are being out-competed by tablets. Seems that this tech is being developed thanks to signage screens as the color e-reader market is too small.
Almost no competition in this size and weight from tablets since the times of Galaxy Tab S2 8" 8 years ago.
Others are either big&heavy or have ugly LCDs. No competition for e-readers.