The High Jump activity of the Athletics skill says the following:
But what if you can Leap farther than you can High Jump? Does a failure really net more range than a success?
For example, I have a human monk with Crane Stance, Dancing Leaf, Powerful Leap, boots of bounding, and a Speed of 55 feet. Together these allow him to Leap horizontally 35 feet or 10 feet vertically. Insofar as I can tell many of those same things don't apply to High Jumps (or at least not in the same way).
It isn't clear to the player what their choice means as it relates to the primary choice they are making which is to be good at the bow.
I think this is wrong. Leap is the action you perform when you take the High Jump activity.
The effects of Crane Stance and Boots of Bounding simply add distance to your Leap, so they work fine when you High Jump.
The 'glitch' here seems to be that since High Jump sets your basic Leap to 5 feet (rather than increasing it by some amount), the Success condition of High Jump just doesn't do anything at all.
If there was an upgrade to Powerful Leap that set your base vertical Leap to 10 feet or something, then yeah High Jump would actively make you worse.