> Trying to restrict updates is in effect trying to prevent the original developer changing the behaviour of an app after installation.

Sounds just like the pre-Internet era to me.

I feel there's a qualitative difference between time-influenced or server-influenced code, and the ability to arbitrarily change the code itself. In the former, control is limited to whatever the dev thought of at the time the software was released. It's the difference between vetting a dev at a particular point in time, versus trusting them in perpetuity.

On Android apps can download and execute arbitrary code anytime they want. The app doesn't need to have the code built in.

They could, but a developer won't design it that way unless they're already trying to sidestep update mechanisms. The point still stands that there's a difference between "I trust the developer now" and "I trust the developer forever".

Same on iOS in certain circumstances - eg. webviews.