NO! They are still perfect and maybe check back in another 25 years’.
The PR, VS and TC series were released almost 30 years’ ago and are STILL in full production today! We’ve been the Australian distributor for almost all that time and we have 25 year old 4PR and 8TC cables as demo cables. When the dielectric is stripped off the copper wire inside is still PERFECT! Zero tarnishing, zero damage.
Of course you may wish to upgrade to a higher performance model and you WILL get a noticeable improvement in sound quality. If you do, then pass on your treasured cables to a family member or friend. (I’m not implying that family members are not friends, so no cheeky emails please). They can get another 25 years out of them and will always remember who gave them the wonderful gift.