I agree.
Unfortunately, the rest of your comment is wrong. Every pixel on an OLED screen has the same pulse width. PWM only adjusts global brightness, not per-pixel brightness. Also, the pulse depth is always 100% (it drops to pure black).
Pulse Width for OLED is kind of equivalent to to adjusting the backlight on an LCD that doesn't have local dimming. It's a global multiplier for individual pixel brightness.
Plasma displays use different pulse widths and frequency on individual pixels. I believe they function more like how you incorrectly believe OLED displays function.