Who is cracking anything? The problem with physical access is that at the end of the day your security is only as good as the flat flex cable transporting your key presses.
This is not some science fiction scenario; look at the "addin boards" they found in CryptoPhones (you know that thing was using secure boot!):
Nobody cares to exploit or modify the software if at the end of the day what you are trying to protect is running across a PCB trace and they have physical access.
Very interesting link, though I'm very disappointing it doesn't include speculation on when/where/how the bug was introduced to the phone. Also, I'm pretty surprised I hadn't come across the info that Wikileaks was bugged. Thanks for sharing.
Mad respect for whoever designed that, for a tailor made small series design that is an incredible piece of work. The component density alone is probably some kind of record. Note the Spartan 6.
That literally seems like it taps the microphone wire to record raw audio signals.
Brilliant, but not a software or hardware issue. (Although actually having the device brick itself if it is opened up would have prevented the bug from being inserted).
Likewise secure PIN pads are easily "defeated" by a camera.
Plenty of TPM devices are encased in epoxy and designed to self destruct if tampered with. And lots of modern day devices (iPhones, game consoles) have stood up to years of attempts to exfiltrate their secrets.
Work arounds are possible, but the industry has, for better or for worse, figured out how to make secure secret stores.
There are a lot of companies that are paid big bucks by nation states to find vulnerabilities and not make them public. NSO for example. So yes Apple only fixes the bugs people or companies find that make them public. But not for the reason you are implying.
This is not some science fiction scenario; look at the "addin boards" they found in CryptoPhones (you know that thing was using secure boot!):
https://www.cryptomuseum.com/crypto/gsmk/ip19/implant.htm
Nobody cares to exploit or modify the software if at the end of the day what you are trying to protect is running across a PCB trace and they have physical access.