@vale You are correct, initial-scale=1 is no longer needed for Safari/iPhone. (Did not test iPad.)

In fact, secretly, in the past *only* initial-scale=1 was required; width=device-width was not. But no one ever took it out of their code.

Except in IE10 Mobile, where initial-scale=1 did not work. But we have long stopped caring about IE10 Mobile.

But now it doesn't matter any more which one you use when the iPhone is concerned.

In case you want to test it yourself:
https://quirksmode.org/m/tests/meta-viewport.html