I’m looking into 10 inch displays right now, but they are already significantly more expensive.
At some point it just drives the price of the end product up too much.
<https://onyxboox.com/boox_mirapro>
Note that the pixel density is markedly lower than other e-ink devices. For smaller devices, e.g., the Poke 5, DPI is more than double at 300 dpi (comparable to a laser printer): 6", E Ink Carta Plus, 16 shades of grey, 1072 × 1448 dots, pixel density - 300 ppi
<https://onyxboox.com/boox_poke5>
Granted: with increased viewing distance, resolution can fall somewhat, but given that areal density falls as the, well, square, this is 4x lower resolution.
The Mira Pro runs an eye-watering $1,750, further impeding the viewing experience. Given price trends on other E-Ink devices, I'm pretty sure that's all but entirely driven by the display cost itself.