Do speaker wires degrade over time ?

Entropy - the universe tends toward maximum disorder. IOW, everything falls apart.

Well if it was equipment, I might consider it, but It's cabling and it's 30 year old technology!! If you can get it in the price range of free to $25, I would do it.

It is a run of transparent audio for around $225.00

Yeah... by oxidation.

If the dialectric is in tact... the insulator isn't broken and revealign the naked conductors, you're in better shape, but even if all seems in tact, without breaks, cracks, etc., along the way you will still not escape the oxidation process.

but just think glaciers. the process routinely is about that slow, and as enescapable. just clean that which is immediately exposed to the air... now and then. Twice a year?. Monthly? it's up to you.

If I were in the worrying mood.... I'd worry about gas prices instead.