But it's like installing a custom HTTPS cert in your OS to inspect potential traffic that malware may use through, say, a Google Doc or Sheet. It's helpful to true professionals dealing with highly sensitive information, but it's ultimately a bigger source of compromise for the vast majority of software users.
I don't think there is an easy answer here. That's why I said I thought it made the world a "touch better" and I can see from your response that you understand the tradeoffs roughly as well as I do based on the wording of your response. The fact is that contemplating these hard tradeoffs belie the underlying truth: Securing computers is hard and getting harder and the stakes keep going up. I can't say if this move by Apple will ultimately be worth it, but I certainly understand the predicament they are in. This is no easy work.