Nightingale Legacy Portal
I can use my climbing picks to climb a vertical surface, but not a steep slope (that can't otherwise be traversed at all). That doesn't seem rational to me. If I can't walk, even slowly, up a slope, I should be able to use my picks.
Yes, climbing is one of the weakest core mechanics. Cliffs and the mountains in desert can be a real PITA because of how slopes are handled. It doesn't add challenge in any meaningful way, it just adds frustration (and is compounded by edge detection and just randomly falling when you reach the top).
In fact climbing a steep slope should be easier than climbing a vertical cliff face.