And yes this nonencrypted shit is totally insecure
And let's not forget the several noclick attacks that can root your iphone with a message :)
Have you checked what it takes to achieve those 0-click root exploits on iOS or Android compared to a desktop Linux distro?
Not even in the same league.
Months vs hours.
I think if the bootloader is overwritable, it could lie to you about reflashing the boot partition...