We have had client apps written in languages with no memory management for decades. The value of the web is that it provides a widely supported API that is fairly "safe" to program in.
And with the exception of AirBnb (which is somewhat out of place in your list for other reasons) none of those web companies wrote an iOS app until they became well-established players. In fact, they're all older than iOS.
And with the exception of AirBnb (which is somewhat out of place in your list for other reasons) none of those web companies wrote an iOS app until they became well-established players. In fact, they're all older than iOS.