That's a good point, what is the first adressable market for such a product to gain first momentum before it can become mainstream. Those seem to be low hanging fruits:

-Writers -Coders/Terminal Users like sysadmins -DIY/Hardware Hackers/Raspberry PI/ESP32/Cyberdeck folks -Productivity Hackers -Health Tech folks -Gadget Lovers -Limited Functionality Devices for Education -Folks with medical pre-conditions who need to use eink (e.g. https://dasung-tech.myshopify.com/blogs/news/how-dasungs-e-i...)

I think there is a market, I am just surprised that we take usual monitor like eye-strain as well as the blue light for granted and haven't done anything against it for years. Even though we are having more display usage than ever.