I feel like there's a more than a few explanations but here are my thoughts
1) They are like golf clubs, each club is used with the same technique to achieve different results depending on the situation
2) People (like myself) are in search of "the perfect" shave, if it even exists, won't know unless I try different things.
The perfect, consistent shave. I might add lol I’ve had some great shaves but to replicate them is the key!