Part of what the OP is asking is whether devices inherently deteriorate * /
self-destruct, even when not being used, or they have to be in use to fail.

The answer is that almost everything eventually falls apart, whether or not
it's in use.

Of all components, I'd expect vacuum tubes to last the longest -- perhaps
hundreds of thousands of years -- simply because glass is highly stable, and
the internal metal elements are in a vacuum, where "...rust doth [not]
corrupt".

* Don't say degrade. Degrade is a transitive verb.