This seems pretty reductionist and zero-sum thinking. Taking your line of reasoning to its end, one would expect there to be a single web framework, and that is

This seems pretty reductionist and zero-sum thinking. Taking your line of reasoning to its end, one would expect there to be a single web framework, and that is evidentially not the case. Additionally you are mixing current state with future state, and most of my comment was focused at the current state of server-side Swift. Defining "sufficient" here is important, and I think that server side Swift's progress meets a bar here that prevents it from being a failure. That might not last though.