If this ever becomes a pressing issue, you can do cell selection and mitochondrial transplants.

As long as mitochondrial damage is not uniform, you can sample for cells with low mtDNA damage and no known-harmful mutations, and base your eggs on those cell lines. Do "in vitro" what natural selection would have done "in vivo", reduce damage accumulation that way - potentially to zero.

And if you really want to, you can make eggs off a "known good mtDNA" cell line, then swap a new nucleus into them (cloning-like process), and get a cell line with target nuclear DNA and known good mtDNA. Mitochondrial replacement therapy. Then make eggs off that hybrid line.

Involved lab work, but, perfectly doable, and rides the same stack you already use for IVF. Mitochondrial replacement is already a known tech, but only worthwhile for cases of known harmful mtDNA anomalies currently. "Good mtDNA" eggs are sourced from donors instead of produced from cell lines currently, but this tech might change that too.