Alyosha2001 I have purposefully never updated the TV, so it is still running Android TV 7.0. It does not have Quick Settings. However, it does have the regular Android TV Settings, and there is a Power Saving entry:
Settings - Power - Eco - Power Saving - [Off, Low, High]
The following captures have been made with brightness set to 5 and light sensor disabled; the distance to the TV is always the same:
Power Saving "Off" (the flicker here seems to be the 60 Hz panel refresh rate flicker):
Power Saving "Low" (20 KHz flicker):
Power Saving "High" (still 20 KHz):