I dunno. The OSD on Dells is pretty simple. You press the topmost button twice, up/down to adjust, lowest button to save and exit. Since my office has windows, I've been doing this two to four times a day on most days for years. Doesn't bother me too much (it's pretty quick though because I largely only use the 0-40 range, which is about 20-120 nits). On my LG it's even quicker, push the joystick back, then forward/back to change, push in or timeout to save and exit.
Some people say they'd like ambient light sensors, but I'm not sure I'd wanna use something like that. Sometimes I do find the changing brightnesses on mobile devices irritating.
Changing this directly in the OS would be a better UX, though.