There’s no reason why humans cannot live to be 200-300 years old. We know roughly what causes aging. We can dramatically increase aging in mice to double their life-expectancy. It’s just a matter of coordinating the resources to pull off such a feat.
This is where big-data comes into play. Telomere length and mitochondrial DNA mutations aren’t the only cause of aging. Their effects on the body’s homeostatic mechanisms come into play too. Just as a single chess-move completely changes the possible lines of a match, so too does a little mitochondrial DNA change completely change how the body coordinates itself. It’s like the butterfly effect.
The good news is that with the ability to make enough precise measurements and crunch enough numbers, we should be able to solve and reverse aging anyways. We might not ever get to other solar systems and galaxies by traveling faster than light, but we might get there by living to be 10,000.