There’s two different purposes for a rulebook. One is to be something that a new player can read and understand how the game works so that they can quickly get to actually playing it. The other is to be a reference to give precise definitions, clarify interactions, etc.
There’s some tension between those two purposes. Often there is a simple, easy-to-understand explanation that covers 95% of cases and a more convoluted and difficult to parse explanation that covers all 100%. Sirlin has said that where there is that tension, he philosophically prefers to optimize for the first purpose over the second.
The result is card text and rulebooks that optimize for the first purpose, and the gaps for the second purpose are filled in by things like the rulings document. In an ideal world the second purpose would be fulfilled by a Technically Precise Rulebook, which was substantially longer than the regular one but gave exact definitions for things like “sacrifice” vs. “destroy”. That sounds like a pain to write, but my hope is that resources like the FAQs at the top of this thread can provide a reasonable approximation.