Related: Set up screen time, and disable password changes and account changes, and set a (different to your regular passcode) screen time passcode. Then you have a separate passcode that keeps sensitive account changes locked.
Account changes doesn't lock changes to your Apple ID for example, it's just about email accounts and pass keychain. Passcode change is not useful, why would a thief do it anyway...
The last time this came up, it was pointed out this too can be bypassed.
How so? That's good to know that it can be bypassed.