Why do Jump and High Jump still have an movement lock?

[CidHeiral]

Therefore, since they're simply 20y range abilities that only give the visual impression of leaping on your target, why do they pause your movement to use them?

Because it makes the ability feel more impactful. The animation locks are so incredibly short now it's not a problem.

On a related note, Starcross has a similar animation of your character leaping off screen but it does NOT have any brief movement lock.

Starcross also looks and feels like crap.