> The stars will die out long before entropy becomes relevant here.
Do you understand what "entropy" is? Even using the purely thermodynamic definition, there is a very real energy cost for preserving complete coherence of the DNA sequence. Certainly, as a dynamic chemical system, the "entropy" present in the DNA molecule itself and its complex environment prohibit the likelihood of perfect sequence coherence over lengthy times. The result of such failures is degradation. One of the most unfortunate results of such losses is, frankly, cancer.
Frankly, for significant extension of human life, a general cancer cure is of critical importance. Or the accumulation of small risk factors is going to accumulate to a near certainty of dangerous cancers, of many different sorts. We already see this among our older citizens!
>> especially since scar tissue accumulates and regrowth of neural tissue has never been mastered.
> Neither which is a permanent problem.
Given the lack of progress for both issues, there's little concrete reason to assume they are _not_ permanent issues.