I'm a law student in the US, so I'm actually privy to this information in the form of all the talks that they have judges and lawyers giving.

You may not assume that the US judiciary is healthy and functioning, but it is not as broken as most international observers (or chronically online Americans) think it is. In particular, if you have been observing the Department for Justice's results recently, you'll notice a few things:

1. Because the Department has been hiring for loyalty and not legal skill, the Department has lost most of its prior prestige. Previously, clerking for the Department was a competitive law school position. Now, the top legal minds then to avoid it. As a result, the quality of legal skill at the Department has decreased, drastically.
2. Judges in the federal judiciary, with the exception of some notable Trump cronies, is actually very willing to uphold existing procedural law and rule against the government. It happens extremely regularly.
3. When judicial orders are ignored, it is almost always temporary and not in any lasting way. Federal judges still do threaten and issue contempt of court penalties and disciplinary referrals to officials who blatantly disobey court orders.

So in short, you are partially correct and partially wrong. The judiciary of the US has shown to be remarkably resilient considering it has withstood two years of a fascist in power and in full control of the legislature.

Yep, and the concern shouldn’t just be for yourself - authorities will clone the phones and then comb your contacts and social media and then add to their systems compiling relational data and use that to target people, often innocent people. Your phone data won’t just be used to harass or inconvenience or stress you out, it’ll be used to harm other people. You should care about that.

Well, as I've quickly learned, pretty much nothing in law is an absolute rule. Judges love making their exceptions.

For chips released in 2018 and 2019. To the best of my knowledge anything newer than a iPhone 11 nothing has yet been found and announced. So 7 years ago. That said you know that if there is some unannounced vulnerability and some spyware company or government knows of it, they are not going to report it.

Yes.

I'm sure they do spend time on Graphene OS, but that's not the same as being successful in cracking it.

I wonder if they spend time on Linux mobile devices, considering how niche they are.

But then again, security through obscurity is not real security, and I'm not aware of any reasonable way to run something like QubesOS on a phone in any way that would be usable.

No, this preserves the phone in an "after first unlock" state. They specifically dont want a phone to reboot or shutdown because then the encryption keys get dumped from memory and require the password to decrypt the keys.

Most smartphones encrypt the majority of their storage these days.

This means there are two states the phone can be in.

BFU, or Before First Unlock, is the most secure. When you power on the phone it has just enough software in unencrypted storage to come on, initialize its hardware, start some background processes, and display an unlock screen. This is the most secure state for the phone. When you type in your password, the password itself decrypts the actual key which is used to decrypt the main storage. Without that password, the data is essentially useless as it cannot be decrypted. Also, most phones are now set up so that if you try the wrong password 10 times, it will erase the main storage encryption key which means the data is completely unrecoverable forever. In general, it doesn't matter what you can exploit BFU because there's very little running to exploit and the storage encryption key is usually stored in a secure enclave, that is a special part of a chip that is designed to resist tampering.

Once you type in your password the first time, the phone is AFU, or After First Unlock. The key to access main storage is held in memory, it is being actively used to read and write from that storage as software is running on the phone like email, background apps, etc. The prompt to unlock the phone looks exactly the same, but in reality the phone is in a much less secure state. There's plenty of software, both system and apps, running for you to try to exploit.

The point here is that if you set the phone to regularly reboot, or to reboot if you haven't logged in in a day or two, each time it reboots it switches back to BFU state.

And so if some government agency has arrested you and seized your phone, you want that reboot to happen because if the phone automatically reboots before they manage to get into it, it becomes much much harder for them to get in.