2 Fries had a really clever ratchet ladder idea. This is a variation.
It's an extension ladder with stirrups that slide up on ratchets one side at a time, same as how a lumberjack climbs trees.
Be a lot lighter because there's no rungs, only the ratcheting stirrup things. The stirrups just slide
along in slots in the inner portion with the ladder tubes/handle containing the ratchet mechanisms. To go down you hold on to handles coming out of those slots that reverse the process, pull them down and the stirrups go down, but only one step at a time as the other side locks until you lift your foot to release it.
So you're only doing one movement, lifting your feet like walking up a regular ladder, but depending on the handles you either go up or down.
The decent handles clearly have arrows pointing down so you can figure it out without having to read instructions. Could also do other decent methods like tilting the stirrups inwards, holding down buttons at the tip of the handles, pulling bike brake looking things or something, but the main thing would be the ascent eliminating all those rungs.
Might be good for firefighters. For the same weight as a regular ladder this might go 3 or 4o times higher.
You could extend it as you climbed like with 2 Fries' idea, but since it's not an A frame ladder like his, you'd need a brace to fold out and hold it away from the wall. Might need multiple braces the taller you go. Actually, don't they have ladders you pull up to their full height with a rope and pulley mechanism? Thought I've seen that. If so that's how you'd extend this.
See link for 2 Fries' idea and what this one would look like.