lockable/unlockable bootloader
quality control of the operating system to make sure it doesn’t contain malware/spyware
#1 without #2 is unsafe.
#2 doesn't exist in android because of apps and vulnerabilities
Apple at least makes a good run at it.
Part of androids locking shit down is to try to make their own run at it.
I honestly think we're all just going about it wrong. Make a new physical sim that is unclonable, undumpable, ultimately secure. Have it key sign financial transactions require a pin and have a physical button. If you don't touch the button and have the pin, it won't process a transaction.