Parkour animation breaks the moment the character’s hands don’t land where the wall actually is. Players won’t articulate it, but they see it instantly.
The problem with authored traversal
A vault animation is authored against one specific ledge height. The player will approach at a slightly different height, a slightly different angle, and a slightly different speed, essentially every time. Play the animation unmodified and hands clip through geometry or grab at empty air.
Motion warping
Unreal’s motion warping retargets an animation’s root motion at runtime toward a real target in the world. The vault is authored once, and warps to whatever the player is actually standing in front of.
Most of the work wasn’t the warping itself — it was detection. Deciding which ledge the player meant, at what approach angle a vault should be offered rather than a climb, and what to do when two candidates overlapped. Getting that wrong doesn’t look like a bug; it looks like the character ignoring you.
Tuning
A great deal of running into walls at slightly wrong angles. There isn’t a substitute for it — the failure cases are all in the margins, and the margins are where players live.