Earlier quoted context omitted.
A short list: 1. fonts too small 2. buttons that do different things depending on how long the button is held down 3. chording - needing to hold down more than one button simultaneously to do something 4. blink speed - slow blink means one thing, fast blink means another. Is that LED blinking "slow" or "fast"? 5. labeling buttons with icons that have no deducible meaning 6. modes 7. having to do the next step within…
Reading each one of these made me silently scream inside. I'm not elderly yet (on the outside, I suppose), but each one of these things is poor UX and makes me absolutely livid.
Many devices I have, once I lose the manual, are simply impossible to use because of the points listed above. My dashcam is simply impossible to use because of this, even though it has a bitmapped display. All it needs is power, menu, up, down, select and with a bitmapped display you can do anything with that. But noooo...