Do MC Cartridges Deteriorate over time

Yeah, huge amount of high end audio sounds great in theory only to completely fall apart in practice. Like cartridges, the suspension should just get all hard and brittle and go to hell just sitting there used or not. But this never seems to happen. The Stanton 681EEE on my Technics from 1976 still works great, and that is a lot older and a lot cheaper than your Clearaudio. 

A good cartridge is like a good watch. Sure they will tell you it needs regular service. But in reality, If it ain't broke....

Suspension damping can change its characteristics overtime. With clean records I have seen styli last over 3000 hours. The only failures I have seen were due to failure of the coil wires at the solder joints. Copper will work harden so vibration at this joint eventually causes failure, This is the one big advantage of gold coils. They will never do this. I had a Sumiko Cartridge fail this way, a Talisman S. If it plays, tracks and sounds good to you it is probably OK.

If it plays, tracks and sounds good to you it is probably OK.

This^^^

My thirty-five yrs old Highphonic MC-R5 outperforms certain modern top cartridges, tracks all the Telarc digital cannons with ease and the sound is just sublime, at 1.1 g VTF. Hard to beat for a modern MC or MM I´d say.

In theory, at least, the elastomers in the suspension can deteriorate over time, particularly if exposed to ozone and other such pollutants.  But, I've heard plenty of cartridges in the thirty year old range that sound fine and have not suffered from such problems. 

Way back in time, I had Shure cartridges that did not seem to last that long even though I was careful with setup and kept my records very clean.  When inspected, the report I got was that the stylus looked almost new, so what I was hearing was either the suspension going bad or stylus wear that was not that easy to see.  Whatever the cause, I have had MUCH better luck with wear with my MC cartridges (good thing, given the MUCH higher prices).

Aside from accidental damage (by far the biggest cause of cartridge failure), most of the better MC cartridges seem to last a very long time.  Most of the non-accidental premature death that I've seen had to do with internal wiring failure (evidenced by one channel going stone dead).