You need physical access AND the device pin. None of these hacks allow you to decrypt the device without the pin. The best you can do is load malware that would grab the pin when the user types it in so the defense for this is if the government ever takes your phone for inspection make sure to reboot it before typing in a pin.

The attack where you implant some kind of backdoor to capture the data is possible even without this exploit, it just makes it easier.

Threat modelling. In most models, if someone has uninterrupted physical access to a device, it's theirs.

Phones are more important in that you want to protect the assets from thieves, so we do add non-destructive physical access to our scope, but it's with a higher bug-bar. Someone being able to take your phone, compromise it, then give it back to you so you can input new assets means that a vulnerability has to be severe to be as important as a minor remote vulnerability.