Ask HN: When will we have robotic limbs that are as functional as real ones?

A few years ago I shattered my ankle. Despite a series of reconstructive surgeries, I am developing worsening arthritis which limits my ability to walk.

The treatments for this aren't amazing for a younger person, and one option to stop the pain that is slowly starting to sound more tempting is a below the knee amputation.

However, my main hobby (rock climbing), depends a lot on ankle movement. You can still do it with a prosthetic foot, but not at the level which I enjoy.

So my question - how long until we have fully working robotic feet that can be guided by the brain and have similar range of motion and strength as the real ones? What are the main challenges that haven't been solved yet?