It won't :) It has a LED backlight. Older LCD screens often had fluorescent backlight, which will and did degrade after hours of use. According to Wikipedia, LEDs are the most popular backlight in LCD screens since 2012.

The idea that LEDs last forever is a myth. LEDs degrade over time. They actually list it on the spec sheet. For example an L70 rated led with a 25k hour life will produce 70% of the light it produced when new after 25k hours.

Recently I replaced 4 Asus monitors with led backlights that were produced in 2014 and 2015. Asus says 300 nits. Tested them when I was calibrating their replacements and they were 110-120 at full brightness.

Monitors color shift and dim as they age... that’s why hardware calibrators exist.