Thing is made such that proper cooling for leds is absent, and first they degrade and later just break.
32" backlight of different brand
Note that boards the led are mounted on are cheap thin ones without any thick copper layers and both diode and boards are attached without any thermal compound, so heat just destroys backlights (common for almost all TVs now).
Also note how few of them are used, profits are the goal.
It looks like you're new here. If you want to get involved, click one of these buttons!