Approximately 80% of the pitches I get are between garbled and incoherent. Even higher in the unsolicited ones.
Consider that your recipient is reading on a small screen and utilize pyramid structure. And don't bury the lede. Many pitches ask for money without saying anything at all about what they are about.
I feel like there's no magic in a pitch. That you just have to tell the VC what problem you're solving. And just expect your VC to get it. Maybe the same pitch can have 2 totally different reactions in different people, because one of them have felt that pain or is identified with it.
Bottom line, my take is: make it simple, be clear and open. There's no need to "sell" or "charm" with it.
Persuasion tactics have almost no place, except at the end when you say, "So, are you in?"
Before that, the hurdle that (as @joshu says) 80% of pitches fail to clear is explaining clearly what the company will do.