The seat angle changes too
Saddle angle stays the same relative to the handlbars though.
So, steep climb, shorten the forks, drops the front end down and you’re sitting more level than you would be, and can get your weight forwards easier.
Steep descent, extend the forks, lifts the front end up (drops the front wheel down), so you’re sitting more level than you would be, can get your weight back easier.
I still don’t see a problem.