What about EFTO training?
Dramatic video indeed.
I remember during the 6-monthly sim checks on the B737 and the A320 that one of the failures which was practiced again and again is Engine-Failure-on-Take-Off (EFTO), usually at V1.
Swift corrective action is required, but the aircraft should (must!) be at a take-off weight sufficiently low to allow a continued climb single-engine at this most precarious point in the flight.
It looks from the video as if the left propellor is rotating more slowly than the right. But the aircraft should still be capable of safe forward flight, albeit on one engine.
The flight recorder will show the truth but initial thoughts suggest that this appalling crash need not have happened.