With OLED screens, this is just fine - massive lifetime, very (VERY) low power consumption that is almost directly proportional to the amount of screen lit up, and brightness thereof!
My Sereies 3 HD TiVo has an OLED display back when OLED was NEW. This device has been on 24/7 for 4 years. The hard drive died last month, requiring an upgrade, but the OLED is bright as day 1.