The bolded part of your question is "What are the game-mechanical benefits of [game feature]?" The rules-as-written tag doesn't apply because your question doesn't seem to be about how the rules are written; it's fundamentally about analysis of how game systems interact in the absence of an explicit statement in the rules. You're asking for expert analysis of what appears to be a concept omitted from the rules.
Let's flip this around and assume the question were about the rules as written, so you add the rules-as-written tag and await answers that do nothing more than cite literal rules. Then either someone would answer with an explicit quote from the rules (unlikely given that you're asking the question to begin with) or the correct answer to the question would be "the rules don't explain the game-mechanical benefit" (which isn't very helpful and wouldn't actually answer the bolded question). So the assumption would be wrong. (Unless those are in fact the sorts of answers you're looking for, but in that case you have an XY problem.)
I'm not an expert in Fate Core, but in my RPG.SE experience your question does not merit the rules-as-written tag because you've either underestimated or misrepresented the intent of your own question. You seem to think that because you have the phrase "in the rules as written" in your final paragraph then that makes the question inviolably about the rules as written. I think the problem is that the final paragraph doesn't appear to match the bolded crux of your question. You're soliciting rules-as-written answers when you're actually requesting expert analysis informed by the official rules. Those aren't the same thing, and the rules-as-written tag is not equivalent to "without homebrew" or "official rules only please."