Thank you for the appreciation @photoncatcher.
I will be answering your questions below.
LG says that OLEDs have a lifespan of 100,000 hours to half brightness, a figure that's similar to LED LCDs.
If you're the type of person who can't stop worrying about the longevity of their TV, then I guess LCD is your only option. Though keep in mind, there's no guarantee about those either, as any glance at Amazon or Internet forums will tell you.
OLEDs have less lifespan compared to LCDs. When we compare modules. It depends on the manufacturer of the OLED as well. If you go for a better module I think lifespan can get close to the LCD. As OLED being a new tech. It still needs improvements. Now QLEDs are launched so I think It will replace OLEDs. But energy usage of an OLED will be less than the LCD.
You can program your OLED accordingly to make it sleep after some time. I will suggest you read the datasheet of your OLED or you can read the below.
display.ssd1306_command(c); // Where c is a value from 0 to 255 (sets contrast e.g. brightness)
display.ssd1306_command(SSD1306_DISPLAYOFF); // To switch display off
display.ssd1306_command(SSD1306_DISPLAYON); // To switch display back on
I think this will help you.
Hope this information helps you.