I love these ideal monitor threads. Not techie enough to go into the more nitty-gritty stuff and am glad that others who are capable have done so but here's my wishlist anyway.
Ultrawide 34" or 38"
3440x1440, 3840x1600, 5120x2160 seem like nice resolutions to focus on or develop, especially with single GPUs now capable of running them (or nearly able).
100Hz refresh rate minimum. Even if you don't game, it's very helpful for older eyes just reading text alone (when combined with other features).
Attachable (optional) soundbars of varying quality, with matching aesthetics, so buyers can choose a budget, medium or high-end soundbar, according to their wallet/need. This way you don't waste any money on inbuilt speakers and can bring down the cost of the monitor a bit. But you provide the option, and can even make a bit more profit selling additional kit, I suppose.
TN/IPS/VA variants (nobody will ever agree on what's better, response time v image quality etc, until Oled maybe).
Flicker Free/no Pulse Width Modulation.
Every monitor that is built from now on should have a Profile Change button, to quickly change between at least three saved profiles (reading, gaming, movies for example). One click - change profile from 1 to 2. Another click - change profile from 2 to 3. And so on. Easy, no messing about. By all means add room for more profiles if feasible.
Much better quality control, plus solid 5 year warranty minimum and good support.
Wishful thinking - develop a more affordable tech to do the job that Freesync and Gsync do, and incorporate it into the monitor. Freesync already pretty affordable, just needs to work with Nvidia card too, and have a better range than it does right now.