development and repair

I cut my finger a few days ago. It stopped bleeding, but the next day I bumped it on something and it bled some more.

I was thinking about how it heals. There are some mechanisms that detect injury and deploy repair processes. But it never goes back exactly to how it was before the injury.

Scar tissue is an obvious example, but I wonder if this is pervasive, essentially because there are different mechanisms for healing than for development.

I wonder if it's difficult for evolution to find healing mechanisms that exactly replicate development mechanisms. If they only approximate, then over time your body (originally patterned through development to function well) is gradually replaced by structures that are trying imperfectly to replicate the original ones.

Could species with low senescence be the ones that keep re-using their developmental mechanisms?

Would that also mean that solving ageing could be nearly impossible because we'd have to design repair mechanisms that perfectly match all the developmental mechanisms?