[bigyabai]

> So it seems to imply that Apple phones today are unbreakable.

Indeed. If you don't control the "unbreakable" security though, then the lock is not for your benefit.

> where does the article discuss "all of these protections"?

You could read the danged article, it's pretty clear about the vulnerability of proprietary mitigations. I hate quoting spoilers verbatim but here you go:

  The sharper you get, the more important the work. But the more valuable the work, the craftier — and more determined — your adversaries. Every attack is more novel than the last. [...] By the time you land an engineering gig at Apple, you are a twitchy, tinfoily mess.

  And it is in this spirit that you develop one of the most secure systems the world has ever known. [...] So adversaries be damned: You finally win on the merits. But who said anything about meritocracy? During the champagne toast, Mr. Fart steps from behind the curtain and pulls the pistol of last resort:

  “Don’t ship this. Or else.”

[Thorrez]

That quote is about building security vs not building security. It's about the government potentially ordering Apple to not build security. It's not about proprietary security vs non-proprietary.

Nothing in the article is saying that HSMs, rate limits, etc are weak.