Imagine someone who flicks all of their putts. This is worse than a controlled push putt with minimal left to right movement, right?
Assuming you're still with me on this, consider that the other putting styles have intricate differences that aren't as exaggerated, and you might not be able to point it out right away, but a lot of putting forms are worse than others. The confidence programs and practice in general are basically to weed out the minor flaws of the putt until you are left with something like a good technique and a good mindset.
Take that a step further and I'm suggesting that there is a technique where after you get it down to its absolute best is still going to be less consistent than another (even if it meant a difference over time and across players of 2-5% missed putts in the circle or something).