If iOS had versioned libraries and separate teams maintaining the older branches, would that really impede the modern toolkit? I realize that expanding the scop

If iOS had versioned libraries and separate teams maintaining the older branches, would that really impede the modern toolkit? I realize that expanding the scope of a project by adding more developers isn't as simple as it seems, but I feel like there ought to be an organizational/development structure that could make this work. I wouldn't even be opposed to older apps running in some sort of seamless-to-the-user virtual machine.