I need an expert to confirm or deny:
I think to remember having read that the telomeres aren't really an issue. That that they get shorter is a consequence, not a reason - they are not needed because death of the cell occurs earlier. I also think to remember there actually is a mechanism (a protein) to extend them, it's just that in places where it wasn't needed it is not used and evolution therefore removed it, because it had no consequence.
I think it was form one of the books of (biochemist) Nick Lane. Myself, I only took the basic bio-chem course so I never got to such advanced specialized topics.
EDIT: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1933587/
> 1. Do telomere biology and telomerase activity determine aging?
> The first aspect to this question is whether differences in aging rates among mammalian species are caused in whole or in part by species-specific differences in telomerase/telomere biology. A very brief consideration of this question will show that this is unlikely.
> There is little evidence that commonly observed changes in older individuals, such as anemia and impaired wound healing, result from impaired cellular proliferation, which would be the anticipated consequence of shortened telomeres
(ofc there is a lot more details to consider)