I see the purpose of technique as a method of swinging the racket that provides control of the shot.
Anyone can hit hard and technique is hardly required at all, but if you want a certain spin and speed on the shot, where you can control it to a certain part of the court.....then good technique is a must to execute this consistently. Correct technique would be matching a type of technique to the intended result. Ex. you need a Topspin technique for topspin and a slice technique for a slice.
I also think it is a mistake to label one way as better for all players, like many try to do with the straight arm Fh. I believe the double bend is better for most players, but don't deny the SA can be very good as well. That said, I believe there are certain important keys. I find that to be the strength of MTM instruction, which only focuses on a very few fundamental items and leaves the rest to style and preference.