Pierre, Wind Skies is a nightmare here, censoring my posting at every turn. You don’t get to see the many hidden posts Windy removes, but a comparison of Windy with Wubbo or the Wright Brothers is unfair to the memory of actual achievement.
As for kPower, no one else knows how to make a power kite pump passively like this.
The skateboard is a true COTS TRL9 regen EV that weighs ~25kg and takes quite a bit force to move in turf. The kite is a COTS TRL9 1.8m2 toy, but a 400m2 COTS ship kite in even better wind higher can do the same sort of action.
Imagine how it will work with larger power kites, with a pilot kite added as needed. Its not just the few seconds of video, its hours of test flying successfully.