They usually go obsolete long before they would "die" ... I am sure there's still some working 8086 machines and TRS-80s out there that still work fine. Wouldn't be able to do anything more than a cheap calculator these days tho ...
The only real thing that is going to cause degradation inside the chip (besides electromigration) would be like cosmic rays or something, and those mostly all get filtered out before they reach earth. A massive solar flare like a Carrington event of 1859 would probably wreck all of them in the world though I imagine ... Humanity truly is at the mercy of the sun.