LCD tvs from 2012 and 2022 just went kaput for no reason.

Most likely bad capacitors. The https://en.wikipedia.org/wiki/Capacitor_plague may have passed, but electrolytic capacitors are still the major life-limiting component in electronics.

MLCC's look ready to take over nearly all uses of electrolytics.

They still degrade with time, but in a very predictable way.

That makes it possible to build a version of your design with all capacitors '50 year aged' and check it still works.

Sadly no engineering firm I know does this, despite it being very cheap and easy to do.

Looks like that plague stopped in 2007? I have a 8 year old LCD that died out of nowhere as well, So I'm guessing wouldn't be affected by this. Could still be a capacitor issue though