I disagree that iOS devices is insecure due to this vulnerability since the attacker still need to pass through iOS device and bitcoin wallet encryption.
IMO the real concern is attacker with physical access (such as worker who repair your phone) could jail break your iOS device or/and put malware which act as keylogger or could access bitcoin private key when user open his/her bitcoin wallet.
It's not really that big of a deal anyway... the jailbreak is "non-persistent" and is
not an "untethered" jailbreak... so simply rebooting your device or switching it off and then on again removes the jailbreak and therefore any "non-signed" software (ie. malware) would cease to function... and it needs to be connected to another device to jailbreak it.
Arstechnica have an interview with the hacker that published the exploit here:
https://arstechnica.com/information-technology/2019/09/developer-of-checkm8-explains-why-idevice-jailbreak-exploit-is-a-game-changer/DG: Somebody could use Checkm8 to install a keylogger on a fully up-to-date iOS device, but the second that they rebooted the phone, that keylogger would be gone, right?
A: Correct. Or it wouldn't work. They left the keylogger there, but iOS would just say: "This app is not authorized to run on this phone, so I'm not going to run it."
In addition, with the "newer" devices that are able to be exploited (I believe devices >= iPhone 6) that have the "Secure Enclave", you still need the device PIN etc to be able to access any private data:
DG: In a scenario where either police or a thief obtains a vulnerable phone but doesn't have an unlock PIN, are they going to be helped in any way by this exploit? Does this exploit allow them to access parts of this phone or do things with this phone that they couldn't otherwise do?
A: The answer is "It depends." Before Apple introduced the Secure Enclave and Touch ID in 2013, you didn't have advanced security protections. So, for example, the [San Bernardino gun man's] phone that was famously unlocked [by the FBI]—the iPhone 5c— that didn't have Secure Enclave. So in that case, this vulnerability would allow you to very quickly get the PIN and get access to all the data. But for pretty much all current phones, from iPhone 6 to iPhone 8, there is a Secure Enclave that protects your data if you don't have the PIN.
My exploit does not affect the Secure Enclave at all. It only allows you to get code execution on the device. It doesn't help you boot towards the PIN because that is protected by a separate system. But for older devices, which have been deprecated for a while now, for those devices like the iPhone 5, there is not a separate system, so in that case you could be able to [access data] quickly [without an unlock PIN].